Certification terms: N
197 study terms starting with N.
197 terms
- N+1 Query ProblemA performance anti-pattern that runs one query to fetch N parent rows and then N more queries to fetch each one's children.Advanced
- N+1 RedundancyA design providing one more component than needed to carry the load, so any single unit can fail or be maintained without impact.Foundational
- N_Port ID Virtualization (NPIV)A Fibre Channel feature allowing a single physical HBA port to register multiple virtual WWPNs and FC IDs with the fabric.Advanced
- Naive BayesA probabilistic classifier based on Bayes' theorem that assumes features are independent given the class.Intermediate
- Name Server Lookup (nslookup)A command-line tool on Windows, Linux and macOS for querying DNS servers.Foundational
- Name Server Record (NS)A DNS record that lists the authoritative name servers for a zone.Foundational
- Named CredentialSetup definition of a callout endpoint URL paired with an external credential, so Apex and flows can call it without handling secrets.Intermediate
- Named Entity Recognition (NER)An NLP task that identifies and classifies entities such as people, organizations, locations and dates in text.Foundational
- NamespaceA Kubernetes mechanism for dividing a cluster into virtual partitions that scope names, policies, quotas, and access control.Foundational
- Namespace PrefixUnique identifier prefixed to components in a package to prevent naming conflicts across orgs.Intermediate
- NAND Flash Cell TypesClasses of flash memory (SLC, MLC, TLC, QLC) defined by how many bits each cell stores.Intermediate
- nanoA simple terminal-based text editor common on Linux and macOS.Foundational
- NAPALMNetwork Automation and Programmability Abstraction Layer with Multivendor support, a Python library offering a unified API across network operating systems.Advanced
- Narrow AI (ANI)AI designed to perform a specific task or narrow set of tasks, as opposed to general human-level intelligence.Foundational
- NAT GatewayManaged network address translation service that lets private-subnet resources initiate outbound internet connections while blocking inbound ones.Foundational
- NAT Traversal (NAT-T)Techniques that let protocols which embed addresses or lack ports, such as IPsec and VoIP, work through NAT devices.Intermediate
- NAT64A translation mechanism that lets IPv6-only clients reach IPv4-only servers by mapping IPv4 addresses into an IPv6 prefix.Advanced
- Nation-State ActorA threat actor sponsored or directed by a government, with high sophistication, funding and strategic goals.Foundational
- National Vulnerability Database (NVD)The US government repository, maintained by NIST, that enriches CVE records with CVSS scores, CWE and CPE data.Foundational
- Native Call QueuingA CUCM hunt pilot feature that queues callers with announcements and music on hold until a line group member is available.Intermediate
- Native VLANThe VLAN whose frames are sent untagged across an 802.1Q trunk, VLAN 1 by default on Cisco.Foundational
- Natural KeyA key made from real-world business data that is already unique, such as an ISBN, VIN or email address; also called a business key.Intermediate
- Natural Language Processing (NLP)The field of AI that enables computers to understand, interpret and generate human language.Foundational
- NCCLNVIDIA Collective Communications Library: optimized multi-GPU and multi-node collectives such as all-reduce.Advanced
- ncclientA Python library for NETCONF client operations against network devices.Intermediate
- Near Field Communication (NFC)Very short-range (about 4 cm) 13.56 MHz wireless communication used for payments, access badges, and pairing.Foundational
- Near-Critical PathA path whose duration is close to the critical path and has little float.Intermediate
- Near-End Crosstalk (NEXT)Crosstalk measured at the same end of the cable as the transmitter, usually caused by poor terminations.Intermediate
- Near-Far ProblemA distant low-power station's signal being drowned out by nearby high-power stations.Advanced
- Need to KnowPrinciple that access to specific information is granted only when it is required for a person's duties.Foundational
- Needs AnalysisThe first phase of an AV project, identifying how clients will use the space, who the users are, and the required functions, budget and constraints.Foundational
- Negative FloatFloat with a value below zero, indicating that the schedule cannot meet a required date.Advanced
- Negative TestingTesting how software behaves with invalid, unexpected or malicious input and conditions.Foundational
- NegotiationDiscussion aimed at reaching an agreement between parties with shared or opposed interests.Foundational
- Neighbor Advertisement (NA)An ICMPv6 type 136 message replying to a Neighbor Solicitation with the sender's link-layer address, or announcing a change.Intermediate
- Neighbor Discovery Protocol (NDP)The ICMPv6-based protocol (RFC 4861) that performs address resolution, router discovery, prefix discovery and duplicate address detection in IPv6.Intermediate
- Neighbor ReportAn 802.11k list of nearby APs (BSSIDs, channels, capabilities) sent to a client to speed roaming.Intermediate
- Neighbor Solicitation (NS)An ICMPv6 type 135 message used to find a neighbor's MAC address, verify reachability, or detect duplicate addresses.Intermediate
- Neighbor ZoneAn Expressway zone that connects to a trusted peer such as CUCM, another Expressway or a gatekeeper on the internal network.Intermediate
- NeMo GuardrailsNVIDIA's open-source toolkit for adding programmable safety, topic and security rails to LLM applications.Advanced
- NERC CIPMandatory North American Electric Reliability Corporation Critical Infrastructure Protection standards for the bulk electric system.Advanced
- NessusA widely used commercial vulnerability scanner from Tenable that uses plugins to detect vulnerabilities and misconfigurations.Foundational
- Nested RAIDRAID levels combining two schemes, such as RAID 50 (striped RAID 5 sets) or RAID 60 (striped RAID 6 sets).Intermediate
- Nested VirtualizationRunning a hypervisor inside a virtual machine so the VM can host its own VMs.Intermediate
- Net Present Value (NPV)The present value of future cash inflows minus the present value of outflows, discounted at a required rate.Intermediate
- Net Promoter Score (NPS)Customer loyalty metric based on likelihood to recommend, scored 0-10: % promoters (9-10) minus % detractors (0-6).Foundational
- net use CommandA Windows command that connects, lists, or removes mapped network drives and shares.Foundational
- net user CommandA Windows command for creating, modifying, and viewing user accounts.Foundational
- NetApp AggregateIn ONTAP, a collection of RAID groups of physical disks owned by one node, providing storage for volumes.Intermediate
- NetApp ONTAPNetApp's unified storage operating system providing NAS and SAN protocols, snapshots, replication and efficiency features.Intermediate
- NetBIOSA legacy API and set of services for name resolution and sessions on Windows networks, using UDP 137, UDP 138 and TCP 139.Intermediate
- NetBoxAn open-source network source of truth for IPAM and DCIM data, with REST and GraphQL APIs used to drive automation.Intermediate
- NETCONFThe Network Configuration Protocol (RFC 6241), an XML-based RPC protocol over SSH (port 830) for installing, manipulating, and deleting device configuration.Intermediate
- NETCONF DatastoresConceptual configuration stores accessed by NETCONF: running, candidate, and startup.Advanced
- NetFlowA Cisco-originated technology that exports metadata about traffic flows, such as addresses, ports and byte counts, to a collector.Intermediate
- NetmikoA Python library that simplifies SSH connections to network devices for sending CLI commands and configuration across many vendors.Intermediate
- netshA Windows command-line tool for viewing and configuring network settings, including Wi-Fi, firewall, and proxies.Intermediate
- Network Access Control (NAC)Technology that authenticates and checks devices before granting network access, enforcing policy at the edge.Foundational
- Network ACL (NACL)Stateless, subnet-level firewall in AWS VPCs with numbered allow and deny rules evaluated in order.Intermediate
- Network AddressThe first address in a subnet, with all host bits set to 0, which identifies the subnet itself.Foundational
- Network Address Translation (NAT)A function that rewrites IP addresses (and often ports) in packet headers as traffic passes through a router or firewall.Foundational
- Network Allocation Vector (NAV)The virtual carrier-sense timer stations set from the Duration field of frames they hear.Advanced
- Network BaselineA record of normal network performance and behavior used to identify anomalies.Foundational
- Network BondingCombining multiple Linux network interfaces into one logical interface for redundancy or increased throughput.Intermediate
- Network Detection and Response (NDR)A solution that analyzes network traffic to detect threats and enable response, often using behavioral analytics.Intermediate
- Network Device Interface (NDI)A Vizrt (formerly NewTek) protocol for low-latency video, audio and control over standard IP networks, common in live production.Intermediate
- Network DiscoveryA Windows setting that lets a PC find and be found by other devices on the network.Foundational
- Network Entity TitleThe IS-IS router address in NSAP format, containing the area ID, system ID and NSEL of 00.Intermediate
- Network File System (NFS)A file-sharing protocol common in Unix and Linux environments, using TCP and UDP port 2049.Intermediate
- Network ForensicsCapturing and analyzing network traffic and logs to investigate security incidents.Intermediate
- Network Interface Card (NIC)The hardware that connects a device to a network, providing a physical connection and a MAC address.Foundational
- Network Layer (L3)OSI Layer 3, which provides logical addressing and routing of packets between different networks.Foundational
- Network Load Balancer (NLB)AWS layer 4 load balancer for TCP, UDP and TLS traffic offering ultra-low latency and static IP addresses per AZ.Intermediate
- Network Location ProfileThe Windows classification of a network as Public or Private (or Domain) that sets firewall and discovery behavior.Foundational
- Network PolicyA Kubernetes resource that controls allowed ingress and egress traffic for selected pods at the IP and port level.Intermediate
- Network PortionThe leading bits of an IP address, identified by the subnet mask, that specify which network or subnet the address belongs to.Foundational
- Network ProgrammabilityUsing software, APIs, and data models to configure, monitor, and operate networks programmatically instead of by CLI.Foundational
- Network Security Group (NSG)Azure set of stateful allow/deny rules filtering traffic to and from resources by source, destination, port and protocol.Foundational
- Network SegmentationDividing a network into separate zones, such as VLANs or subnets, with controlled traffic between them.Foundational
- Network SlicingCreating multiple logical end-to-end networks with distinct characteristics on shared 5G infrastructure.Advanced
- Network Statistics Command (netstat)A command that shows active connections, listening ports, routing tables and interface statistics.Foundational
- Network Time Protocol (NTP)A protocol that synchronizes clocks across network devices and hosts, using UDP port 123.Foundational
- Network TopologyThe arrangement of nodes and links in a network, described physically (cabling) or logically (data flow).Foundational
- Network Traffic Analysis (NTA)Monitoring and analyzing network traffic to detect anomalies, threats and performance issues.Intermediate
- Network Troubleshooting MethodologyThe structured seven-step process: identify the problem, establish a theory, test it, plan, implement, verify functionality and document.Foundational
- Network-Attached Storage (NAS)A storage device connected to a network that provides file-level access using protocols such as SMB and NFS.Foundational
- Network-Based Application Recognition (NBAR2)Cisco deep packet inspection engine that identifies applications (over 1,500 protocols) for classification and visibility.Intermediate
- NetworkManagerThe default Linux network configuration daemon, managed with nmcli, nmtui or GUI tools.Intermediate
- Neural Network (NN)A model made of layers of interconnected artificial neurons that learn weighted transformations of input data.Foundational
- Next ExperienceServiceNow's modern unified UI framework (Polaris) with a new header, menus, themes and workspaces.Foundational
- Next Hop Resolution Protocol (NHRP)A protocol that maps overlay tunnel addresses to underlay NBMA addresses, acting like ARP for DMVPN.Advanced
- Next-Generation Antivirus (NGAV)Endpoint antimalware that uses machine learning, behavioral analysis and exploit prevention instead of relying solely on signatures.Foundational
- Next-Generation Firewall (NGFW)Firewall that adds application awareness, user identity, intrusion prevention, and threat intelligence to stateful inspection.Intermediate
- Next-Hop-SelfA BGP neighbor option that rewrites the NEXT_HOP to the router's own address when advertising to iBGP peers.Intermediate
- Next-Token PredictionThe training objective of predicting the next token in a sequence given the preceding tokens.Intermediate
- NEXT_HOP AttributeA well-known mandatory BGP attribute giving the IP address to forward toward for a prefix.Intermediate
- NexusScrum.org framework for 3 to 9 Scrum Teams working on a single product with a single Product Backlog.Advanced
- Nexus Integration Team (NIT)Team in Nexus accountable for ensuring a done Integrated Increment is produced at least once every Sprint.Advanced
- nftablesThe modern Linux netfilter framework and nft command that replace iptables, ip6tables, arptables and ebtables.Advanced
- NIC TeamingCombining multiple NICs on a host into one logical interface for redundancy, load balancing or both.Intermediate
- Nice ValueA Linux process scheduling priority from -20 (highest priority) to 19 (lowest) that influences CPU time allocation.Intermediate
- NIS2 DirectiveEU Directive (2022/2555) imposing cybersecurity risk-management and incident-reporting obligations on essential and important entities.Intermediate
- NIST AI 600-1NIST Generative AI Profile (July 2024) applying the AI RMF to risks unique to or exacerbated by generative AI.Advanced
- NIST AI Risk Management Framework (AI RMF)A voluntary U.S. NIST framework for managing AI risks, organized into Govern, Map, Measure and Manage functions.Intermediate
- NIST Cybersecurity Framework (CSF)A NIST framework of cybersecurity outcomes organized into six functions: Govern, Identify, Protect, Detect, Respond and Recover.Foundational
- NIST Cybersecurity Framework 2.0 (NIST CSF 2.0)Voluntary NIST framework (Feb 2024) organizing cybersecurity outcomes into six functions: Govern, Identify, Protect, Detect, Respond, Recover.Foundational
- NIST Definition of Cloud Computing (NIST SP 800-145)The NIST special publication that defines cloud computing via 5 essential characteristics, 3 service models and 4 deployment models.Foundational
- NIST IR 8547NIST report setting the timeline to deprecate and then disallow quantum-vulnerable public key algorithms.Advanced
- NIST Privacy FrameworkVoluntary NIST tool for managing privacy risk through enterprise risk management, structured like the Cybersecurity Framework.Intermediate
- NIST SP 800-115NIST's Technical Guide to Information Security Testing and Assessment, covering review, target identification and vulnerability validation techniques.Intermediate
- NIST SP 800-137NIST guidance on Information Security Continuous Monitoring (ISCM) for federal systems and organizations.Advanced
- NIST SP 800-171NIST requirements for protecting the confidentiality of CUI in nonfederal systems and organizations.Intermediate
- NIST SP 800-171ANIST assessment procedures for verifying the security requirements of NIST SP 800-171.Advanced
- NIST SP 800-172NIST enhanced security requirements for protecting CUI against advanced persistent threats.Advanced
- NIST SP 800-30NIST guide for conducting information security risk assessments for federal systems and organizations.Intermediate
- NIST SP 800-37NIST publication defining the Risk Management Framework for information systems and organizations.Intermediate
- NIST SP 800-39NIST guidance on managing information security risk at organization, mission, and system tiers.Advanced
- NIST SP 800-53NIST catalog of security and privacy controls for information systems and organizations.Intermediate
- NIST SP 800-53ANIST guide for assessing security and privacy controls, defining assessment procedures and methods.Advanced
- NIST SP 800-53BNIST publication defining control baselines for low, moderate, and high impact systems and a privacy baseline.Advanced
- NIST SP 800-60NIST guide mapping types of information and systems to security categories.Advanced
- NIST SP 800-61The NIST publication providing guidance on computer security incident handling and response.Intermediate
- NIST SP 800-82NIST's Guide to Operational Technology Security, providing recommendations for securing ICS and other OT systems.Intermediate
- NISTIR 8259NIST's foundational guidance on cybersecurity activities and capabilities that IoT device manufacturers should provide.Advanced
- Nit (cd/m2)A unit of luminance equal to one candela per square meter, used to specify display brightness.Foundational
- NmapA widely used open-source network scanner for host discovery, port scanning, service detection and OS fingerprinting.Intermediate
- NodeA worker machine, virtual or physical, in a Kubernetes cluster that runs pods.Foundational
- Node AffinityKubernetes rules that constrain which nodes a pod can be scheduled on based on node labels.Intermediate
- Noise FloorThe ambient level of background RF energy on a channel, measured in dBm.Foundational
- Nominal Group Technique (NGT)Group technique that enhances brainstorming with a voting process to rank the most useful ideas.Intermediate
- Non-Additive MeasureA fact that cannot be summed across any dimension, such as percentages, ratios or unit prices.Intermediate
- Non-Credentialed ScanA vulnerability scan performed without logging in, seeing only what is exposed over the network.Foundational
- Non-Disclosure Agreement (NDA)A legally binding contract that obligates parties to keep shared confidential information secret.Foundational
- Non-Functional Requirement (NFR)A requirement describing conditions or qualities the solution must have, such as performance, security, usability, or availability.Foundational
- Non-Overlapping ChannelsChannels whose spectrum does not overlap, such as 1, 6, and 11 in the 2.4 GHz US band.Foundational
- Non-Persistent DesktopA VDI desktop that reverts to a clean golden image at logoff, with user data and profiles kept separately.Foundational
- Non-Repeatable ReadAn anomaly in which reading the same row twice in one transaction returns different values because another transaction committed a change in between.Intermediate
- Non-repudiationAssurance that a party cannot credibly deny having performed an action, such as sending a message or signing a document.Foundational
- Non-Uniform Memory Access (NUMA)A multiprocessor memory architecture in which each CPU socket has local memory that it accesses faster than another socket's memory.Advanced
- Non-Volatile Memory Express (NVMe)A storage protocol designed for flash that connects SSDs over PCIe with deep parallel queues and low latency.Foundational
- Non-Wi-Fi InterferenceRF energy from devices that do not use 802.11, such as microwave ovens, Bluetooth, and cordless phones.Intermediate
- NonceA 'number used once' that ensures uniqueness in a cryptographic operation to prevent replay and keystream reuse.Intermediate
- Nonclustered IndexA separate index structure containing key values and pointers to the data rows; a table can have many.Intermediate
- NonconformityNon-fulfillment of a requirement of a standard, regulation, or the organization's own management system.Intermediate
- Nonstop Routing (NSR)A high-availability feature where the standby route processor maintains full routing protocol state so neighbors never notice a switchover.Advanced
- Normal ChangeChange requiring full assessment, authorization and scheduling, often reviewed by CAB.Foundational
- Normal DistributionA symmetric, bell-shaped continuous probability distribution fully described by its mean and standard deviation.Foundational
- NormalizationMin-max scaling that rescales a feature to a fixed range, usually 0 to 1.Foundational
- North Star MetricThe single metric that best captures the core value a product delivers to customers.Intermediate
- North-South TrafficTraffic that enters or leaves a data center or network, moving between internal systems and external clients.Intermediate
- Northbound and Southbound APIsController interfaces: northbound APIs face applications and users, while southbound APIs face network devices.Foundational
- Northbridge and SouthbridgeLegacy two-chip chipset design where the northbridge handled fast components and the southbridge handled slower I/O.Intermediate
- NoSQL DatabaseA non-relational database that stores data as key-value pairs, documents, wide columns or graphs, usually with a flexible schema.Foundational
- NoSQL InjectionInjection against NoSQL databases such as MongoDB, where crafted input alters query operators or logic.Intermediate
- NOT EXISTSA predicate that is true when a correlated subquery returns no rows; the NULL-safe way to write an anti join.Intermediate
- NOT NULL ConstraintA constraint requiring that a column always contains a value.Foundational
- Not-So-Stubby Area (NSSA)An OSPF stub-like area that blocks Type 5 LSAs but allows a local ASBR to inject externals as Type 7 LSAs.Advanced
- Notable EventAn event generated by a Splunk Enterprise Security correlation search that requires analyst review.Intermediate
- NotificationEmail or push message sent when a record is inserted, updated or an event fires, to specified users, groups or fields.Foundational
- NotPetyaA 2017 destructive wiper disguised as ransomware that spread from a compromised Ukrainian accounting software update.Intermediate
- Now AssistServiceNow's generative AI capabilities for summarization, resolution notes, search, code generation and conversational experiences.Foundational
- NT LAN Manager (NTLM)Legacy Microsoft challenge-response authentication protocol, now deprecated in favor of Kerberos.Intermediate
- ntdsutilA command-line tool for AD database maintenance, FSMO role seizure, metadata cleanup, snapshots and authoritative restore.Advanced
- NTFSThe New Technology File System, the standard journaling filesystem for Windows with permissions, encryption, compression and quotas.Foundational
- NTFS PermissionsFile and folder access controls on NTFS volumes, such as Full Control, Modify, Read and Execute, applying both locally and over the network.Foundational
- NTILE FunctionA window function that divides ordered rows into a specified number of roughly equal buckets and returns each row's bucket number.Advanced
- NTP StratumThe distance of an NTP server from an authoritative reference clock, from stratum 0 (the clock) to 15; stratum 16 means unsynchronized.Intermediate
- NULLA marker meaning a value is missing or unknown; it is not zero, an empty string or false.Foundational
- Null Data FrameA data frame with no body, used by clients to signal power-save state changes to the AP.Advanced
- Null Data Packet (NDP)A PHY frame without a data payload used for channel sounding and other measurements.Advanced
- Null Hypothesis (H0)The default assumption of no effect, no difference or no relationship, which a test tries to find evidence against.Foundational
- Null Pointer DereferenceAccessing memory through a pointer whose value is null, typically causing a crash and denial of service.Intermediate
- Null0 InterfaceA virtual Cisco interface that discards traffic routed to it, used for summary and blackhole routes.Intermediate
- NULLIF FunctionA function that returns NULL if its two arguments are equal, otherwise the first argument.Intermediate
- NullingNear-total cancellation of a signal caused by multipath copies arriving 180 degrees out of phase.Advanced
- Number MatchingPush MFA enhancement requiring the user to enter a number shown on the sign-in screen into the authenticator app.Intermediate
- Number of Subnets FormulaThe calculation 2^s, where s is the number of borrowed subnet bits, giving how many subnets are created.Foundational
- Nutanix AHVNutanix's enterprise KVM-based hypervisor included with the Nutanix Cloud Platform.Intermediate
- Nutanix PrismNutanix's management interface, with Prism Element managing a single cluster and Prism Central managing multiple clusters.Intermediate
- NVIDIA AI Enterprise (NVAIE)NVIDIA's licensed, supported software suite for developing and deploying production AI, including NIM, NeMo and Triton.Intermediate
- NVIDIA BlackwellNVIDIA's GPU architecture following Hopper, used in B200, B300 and GB200/GB300 systems, adding FP4 and fifth-generation NVLink.Intermediate
- NVIDIA CosmosNVIDIA's platform of world foundation models for generating and understanding physical-world video and data.Advanced
- NVIDIA DGXNVIDIA's integrated AI systems combining GPUs, NVLink, networking and an optimized software stack.Intermediate
- NVIDIA DGX SuperPODNVIDIA's reference architecture for scalable AI supercomputers built from DGX systems, InfiniBand or Ethernet fabrics and storage.Advanced
- NVIDIA DynamoNVIDIA's open-source distributed inference framework for serving reasoning and generative models across many GPUs.Advanced
- NVIDIA HopperNVIDIA's GPU architecture behind the H100 and H200, introducing FP8 Transformer Engine and fourth-generation NVLink.Intermediate
- NVIDIA NeMoNVIDIA's framework and microservices for building, customizing, evaluating and guarding generative AI models and agents.Intermediate
- NVIDIA NGCNVIDIA's catalog of GPU-optimized containers, pretrained models, Helm charts and SDKs.Intermediate
- NVIDIA NIMNVIDIA Inference Microservices: prebuilt, optimized containers that serve AI models through industry-standard APIs.Intermediate
- NVIDIA OmniverseNVIDIA's platform for building and operating physically accurate 3D simulations and digital twins based on OpenUSD.Advanced
- nvidia-smiNVIDIA System Management Interface: a command-line tool to query and manage GPU state.Intermediate
- NVLinkNVIDIA's high-bandwidth, low-latency GPU-to-GPU interconnect.Intermediate
- NVMe over Fabrics (NVMe-oF)An extension of NVMe that carries NVMe commands across networks such as RDMA, Fibre Channel or TCP for low-latency shared flash storage.Advanced
- NVMe/TCPAn NVMe-oF transport that runs NVMe over standard TCP/IP Ethernet networks without requiring RDMA or lossless configuration.Advanced
- NVSwitchAn NVIDIA switch chip that connects multiple GPUs over NVLink for all-to-all full-bandwidth communication.Advanced
- NYDFS Cybersecurity RegulationNew York Department of Financial Services rule (23 NYCRR Part 500) requiring covered financial entities to maintain cybersecurity programs.Advanced
- Nyquist TheoremThe rule that a signal must be sampled at least twice its highest frequency to be reconstructed accurately.Foundational