N+1
A configuration of clustered servers or storage subsystems that provides redundancy for improved reliability by using multiple primary systems and one backup system. This provides for improved scalability and reduced cost compared to two-times (1+1) configurations.

NACHA (National Automated Clearing House Association)
A financial industry organization that develops electronic solutions to improve the payments system. Although it has retained the "NACHA" acronym, the organization now uses "NACHA — The Electronic Payments Association" as its full name.

NAI (Network Associates Inc.)
A network security vendor headquartered in Santa Clara, California.

NAP (network access point)
The point from which an Internet service provider (ISP) drops down its lines and establishes a peering arrangement to provide Internet connectivity to customers. See ISP.

narrowband
Communications bandwidth that is narrower than broadband; typically, voice grade or lower. See broadband.

NAS (network-attached storage)
A category of storage products in which the requisite hardware and software comes bundled into an integrated product, which is optimized for use as a dedicated file or storage management server attached to the enterprise's network. Ideally, NAS is platform- and operating-system-independent, appears to any application as another server, can be brought online without shutting down the network and requires no changes to other enterprise servers.

NAT (network address translation)
A function that translates the Internet Protocol (IP) addresses used in an internal IP network's addressing structure to fewer, external Internet IP addresses.

NCA (Network Computing Architecture)
A computing architecture promoted by Oracle in the late 1990s. NCA anticipated market trends toward multitier, service-oriented architectures, component software and Internet-derived technology. But NCA wasn't fully implemented in Oracle's products and never gained sufficient industry support.

NDC (networked data center)
A service that goes beyond making data center functionality available on a network. An NDC employs networking technology to treat multiple data centers and the network as a single system to efficiently access and process applications.

NDMP (Network Data Management Protocol)
A standard protocol — proposed by storage technology vendors Network Appliance and Legato Systems — that storage management applications can use to back up data in a network of heterogeneous servers. NDMP defines a standard agent that can operate on any file server, regardless of hardware platform or operating system. NDMP is used only to provide a tape backup and, to some extent, a disk backup approach for network-attached storage (NAS) systems built on proprietary operating systems; it is not needed with Windows-based NAS or storage area networks (SANs). See NAS and SAN.

NDS (Novell Directory Services)
A globally oriented service that maintains information about network resources (including users, groups, servers, volumes, printers and multiple servers) and provides a naming service. NDS (previously called "NetWare Directory Services") replaces the binary file used in previous versions of Novell's NetWare network operating system.

nearshore
An outsourcing term describing the provision of services from a country that is close to the client enterprise's country — for example, services provided to a U.S. enterprise from a service provider located in Mexico. See offshore.

.NET
A major software initiative launched by Microsoft in 2000. At its core, .NET represents Microsoft's implementation of the Web services concept, which treats software as a set of services accessible over ubiquitous networks using Web-based standards and protocols — although Microsoft has broadly applied the ".NET" moniker to several independent technologies and initiatives that have little to do with Web services. As a software infrastructure, .NET consists of two new programming models:

See Web services, SOAP, WSDL, UDDI and CLR.

NetBEUI (NetBIOS Extended User Interface)
A device driver and transport protocol, originally developed by Microsoft, that can bind with up to eight Media Access Control (MAC) drivers. See MAC.

NetBIOS (Network Basic Input/Output System)
An application programming interface for network operations on a personal computer, originally developed for IBM and compatible PCs running Disc Operating System (DOS). See BIOS and DOS.

NetMeeting
A data conferencing and groupware facility for Microsoft Windows.

NetView
An network management product introduced by IBM in the early 1990s, and later transferred to its Tivoli Systems subsidiary. Now that Tivoli is an IBM software brand rather than a separate company, the product's name formal name is "IBM Tivoli NetView."

NetWare
A network operating system (NOS) from Novell. It is the dominant local-area networking (LAN) system for peripheral sharing and application communications. See LAN and NOS.

network
Any number of computers (such as PCs and servers) and devices (such as printers and modems) joined together by physical or wireless communications links. In the enterprise context, networks allow information to be passed between computers, regardless of where those computers are located. Networks provide the roads for information traffic (such as sending files and e-mail) within a corporate environment, and allow users to access databases and share applications residing on servers. If a network does not go outside of a company building, or campus, then it is known as a local-area network (LAN). If it has a bridge to other outside networks, usually via lines owned by public telecommunications carriers like AT&T, then it is known as a wide-area network (WAN). See LAN and WAN.

network appliance
A type of computing appliance that aids in the flow of information to other network-connected computing devices. Services that may be provided by a network appliance include firewall functions, caching, authentication, network address translation and IP address management. Examples include Blue Coat Systems' caching appliance and WatchGuard Technologies' Firebox firewall appliance. See computing appliance.

network computing
A client/server application architecture with dynamic application deployment, execution and management. Network computing is characterized by four properties: dynamic cached propagation, "write once, run anywhere" operation, automatic platform adjustment and network context storage.

networking
The linking of a number of devices, such as computers, workstations and printers, into a network for the purpose of sharing resources. See network.

network layer
Layer 3 in the Open Systems Interconnection (OSI) model; the logical network entity that services the transport layer. It is responsible for ensuring that data passed to it from the transport layer is routed and delivered through the network. See OSI.

network management
Administrative services performed in managing a network — for example, network topology and software configuration, downloading of software, monitoring network performance, maintaining network operations, and diagnosing and troubleshooting problems.

Network Management Forum (NMF)
Now known as the TeleManagement Forum (see TMF).

network redundancy
A communications pathway that has additional links to connect all nodes in case one link goes down.

network security
Measures taken to protect a communications network from unauthorized access to, and accidental or willful interference of, regular operations.

network topology
Describes the physical and logical relationship of nodes in a network, the schematic arrangement of the links and nodes, or some hybrid combination thereof.

neural net
An artificial-intelligence processing method within a computer that allows self-learning from experience. Neural nets (also known as "neural networks") can develop conclusions from a complex and seemingly unrelated set of information.

newsgroup
On the Internet, one of over 16,000 discussion forums collectively known as Usenet. See Usenet.

NFS (Network File System)
A method of sharing files across a computer network. Pioneered by Sun Microsystems, it is now a de facto standard in the Unix environment. NFS is built on Transmission Control Protocol/Internet Protocol (TCP/IP) and Ethernet.

NGI (Next-Generation Internet)
A U.S. federal government project to fund research and to build a high-speed network designed to provide performance guarantees.

NHID (national healthcare identifier)
An identification code, unique to each person, that provides a way to seamlessly aggregate healthcare data on a given person regardless of the location of the data or the systems used to access it. A standard for such a code — the Universal Healthcare Identifier (UHID) — has been proposed by the American Society for Testing and Materials' (ASTM's) Committee on Healthcare Informatics. See UHID and ASTM.

NIC (network interface card)
The bus-specific adapter that connects an end station or server to a local-area network (LAN). It plugs into an expansion slot on a workstation or server that is to be networked, and has a connector for the network cabling.

NIH (not invented here)
An informal term used to describe a vendor's reluctance or refusal to support technologies it did not develop itself.

NiMH (nickel metal hydride)
A type of rechargeable battery used in portable computers, cell phones and other portable electronic devices. NiMH batteries have greater charge density than nickel-cadmium batteries.

NIS (Network Information Service)
A Sun Microsystems Unix repository for user and resource configuration information.

N-ISDN (Narrowband ISDN)
Integrated Services Digital Network (ISDN) technology based on a top access speed of DS1, which translates into 1.544 megabits per second (Mbps) in a T1 environment and 2.048 Mbps in an E1 environment. Both T1 and E-1 are narrowband in nature. See ISDN, B-ISDN, DS1, T1 and E1.

NIST (National Institute of Standards and Technology)
An agency of the U.S. Department of Commerce; previously called the National Bureau of Standards.

NLM (NetWare Loadable Module)
Software that provides additional functions to a NetWare server — for example, an application (such as a database management system) running directly under NetWare.

NLO (net-liberated organization)
A Gartner concept describing an organizational philosophy enabled by the advent of the Internet and related Web technologies. Rather than "bolting on" Web initiatives to mainstream operations (that is, integrating the Internet into business processes, but leaving the structure of these processes intact) an NLO uses these technologies to liberate itself from the constraints of traditional business environments that focus on local and physical infrastructures. The goal of an NLO is to transform the enterprise into one that is more agile, and thus better able to meet customer demands. As such, the Internet is the primary enabler of liberating organizations from constraints associated with:

NLP (natural-language processing)
The process of converting narrative text to coded facts. Typically, a body of information — such as a series of publications, reports or even a collection of messages — is analyzed and the results displayed as dominant associations or relationships, and show which topics or subjects occurred most frequently.

NLS (natural-language search)
A search in which users enter questions in natural human language, rather than using Boolean operators or other notations (see Boolean). An NLS search engine uses algorithms to translate the question into search logic and attempts to return results that answer the question. The success of these attempts is typically mixed, depending on the complexity and nuances of the question and sophistication of the engine's translation capabilities.

NLS (national language support)
Support for local languages in system or application user interfaces (also known as "native-language support").

nm (nanometer)
One-billionth of a meter; a microscopic measurement commonly used in electronic circuitry.

NMC (network management center)
The center used for control of a network. It may provide traffic analysis, call detail recording, configuration control, fault detection and diagnosis, and maintenance.

NMF (Network Management Forum)
The former name of the TeleManagement Forum (see TMF).

NMOS (N-channel metal-oxide semiconductor)
A microelectronic circuit used for logic and memory chips and in complementary metal-oxide semiconductor (CMOS) design. NMOS transistors are faster than the P-channel metal-oxide semiconductor (PMOS) counterpart, and more of them can be put on a single chip. See CMOS and PMOS.

NMR (nuclear magnetic resonance)
A medical imaging technology that can "see" soft tissue.

NMS (network management system)
A central set of programs providing network-based control of disparate hardware elements; also, the software and hardware used in bridging, routing and other network functions.

NNI (network-to-network interface)
A term used to denote the interface between two public frame relay or asynchronous transfer mode (ATM) networks. See frame relay and ATM.

NNM (Network Node Manager)
A network management product from Hewlett-Packard (HP); part of HP's OpenView product line.

NNTP (Network News Transport Protocol)
The discussion database standard that governs Usenet newsgroup distribution on the Internet.

NOC (network operations center)
A Web-hosting term which refers to the "central nervous system" of the data center. Without it, there would be no infrastructure to transport data to the Web. All Tier 1 Internet service providers and many major telecommunications companies have developed, or are developing, NOCs.

node
A termination point for two or more communications links. The node can serve as the control location for forwarding data among the elements of a network or multiple networks, as well as performing other networking and, in some cases, local-processing functions. Nodes can be host processors, communications controllers, cluster controllers, workgroup computers or terminals.

noise
Unwanted electrical signals, introduced by circuit components or natural disturbances, that tend to degrade the performance of a communications channel.

nonblocking
Describes the state of a telephone switch where a through traffic path always exists for each attached station. Generically, it describes a switch or switching environment designed to never experience a busy condition due to call volume.

nonrepudiation
A security feature under which the origin of data cannot be denied, and can be proven to an independent third party.

NonStop
A computing architecture developed by Tandem Computers, based on a massively parallel system hardware architecture with no single point of hardware failure, and process and data replication. NonStop servers are now a Hewlett-Packard (HP) product line, following HP's acquisition of Compaq Computer, which bought Tandem in 1997.

NonStop SQL (NonStop Structured Query Language)
Relational database management system (RDBMS) software developed by Tandem Computers, and now sold by Hewlett-Packard. NonStop SQL supports near-linear expandability and high uptimes for applications by tolerating single points of failure. NonStop SQL was the first RDBMS to support-engine-based (as opposed to front-end-tool-based) distributed databases. See SQL.

nonvolatile
Term used to describe a data store that retains data when the power is off.

NOS (network operating system)
A set of software utilities that, working in conjunction with an operating system, provides the local-area network (LAN) user interface and controls network operation. A NOS communicates with the LAN hardware and enables users to communicate with one another and to share files and peripherals. Typically, a NOS provides file-to-print services, directory services and security.

notebook
A computer system designed for portability. It comes with a battery and typically measures 8.5 inches by 11 inches and weighs less than 8 pounds with the battery and weight-saver modules. Notebooks use flat-panel color screens of Super Video Graphics Array (SVGA) resolution or higher. They offer expansion through PC-Card technologies and have specialized integrated pointing devices. Types of notebooks include:

NPPI (nonpublic personal information)
Company-held information on individuals that is not in the public domain. Examples include financial information provided by a consumer to a financial institution, resulting from a transaction made by, or a service provided to, the consumer. The disclosure of NPPI is a concern of privacy advocates and various forms of legislation.

NPV (net present value)
Given an initial investment, a series of expected cash flow returns per period, analyzed against an internal opportunity cost of capital. NPV analysis helps determine whether an investment should be made.

NRE (nonrecurring engineering)
A type of fee charged by a firm that has designed an electronic component to a manufacturer that uses that component in its products.

nrt-VBR (non-real-time variable bit rate)
An asynchronous transfer mode (ATM) service category, defined by the ATM Forum, that provides latency or bandwidth guarantees for traffic with no strict timing requirements. Good uses of this service are for legacy Systems Network Architecture (SNA) traffic or frame relay committed information rate (CIR) trunking. See ATM, SNA and CIR.

NSA (National Security Agency)
A U.S. government agency responsible for electronic intelligence.

NSAP (network service access point)
In the semantics of the Open Systems Interconnection (OSI) addressing scheme, the point at which the OSI network service is made available to the transport entity. See OSI.

NSM (network and system management)
The intersection of networking, network management and system management. The vision of NSM (also known as "networked system management")is to enable the management of a distributed set of systems in a fashion similar to that in which many centralized data centers are managed.

NSP (network service provider)
Any provider of network services, including regional Bell operating companies (RBOCs), interexchange carriers (IXCs) and Internet service providers (ISPs). See RBOC, IXC and ISP.

NT1
An Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) line-terminating device at the subscriber's location that provides line maintenance access, timing and echo cancellation. NT1s may be built into other pieces of equipment or may stand alone. See ISDN and BRI.

NTFS (NT File System)
The native file system used in Windows NT, Windows 2000 and Windows Server 2003. NTFS allows permissions to be assigned to individual files and folders.

NTS (NT Server)
The server edition of the Windows NT operating system launched by Microsoft in the 1990s. Later versions are branded as Windows 2000 Server and Windows Server 2003.

NTSC (National Television System Committee)
A specification for video transmission. See CIF (Common Intermediate Format).

NTW (NT Workstation)
The client-side edition of Microsoft's 32-bit Windows NT operating system. See Windows NT.

NUMA (nonuniform memory access)
A technology that extends the performance range of symmetric multiprocessing (SMP) servers. NUMA has become a mainstream technology for high-end Unix servers. See SMP.

NVRAM (nonvolatile RAM)
A type of random-access memory (RAM) that retains its data when power is turned off. See RAM.