Glossary of Computer Hardware Terms - The Letters N & O

NetBEUI - NetBIOS Extended User Interface

A networking protocol used primarily with Windows NT and suited to small peer-to-peer networks.

NetBIOS - Network Basic Input / Output System

A commonly used networking protocol originally developed for LANs. Operates on the Session and Transport layers of the OSI model, so doesn't make use of physical network characteristics.

Network

A system in which multiple computers and linked for the purpose of sharing data and peripherals, like hard disks and printers.

Network Interface Card (NIC)

An adapter installed in an expansion slot or integrated onto the motherboard and allows the computer to connect to a network.

North Bridge

The main portion of the motherboard chipset that acts as an interface between the processor and other parts of the motherboard. It contains the cache, main memory, and AGP controllers, as well as the PCI and AGP buses.

Notebook Computer

A very small computer, approximately the size of a notebook used for writing. The term is often used interchangeably with "laptop", but is technically the much smaller version.

OEM - Original Equipment Manufacturer

Any manufacturer that sells its product to a reseller. Most often refers to the original manufacturer of a device or component, but certain products licensed as OEM, like Windows operating systems, extend the term to mean a complete computer as assembled by an individual for resale.

Operating System (OS)

A collection of programs for operating a computer. An OS performs basic tasks like input and output, as well as more advanced ones like providing an extensive architecture for other programs to inter-operate with it, as well as with the peripheral devices.

Optical Disk

A disk that encodes data as a series of reflecting pits that are read and written by a laser beam.

OSI - Open Systems Interconnection

A reference model developed by the International Organization of Standardization. It splits networking into seven layers which provide specific services and communications standards.

Output

Information that has been processed by the computer and is then sent to an output device, like a hard disk, video display, printer or modem.

Overclocking

The act of running a device like a processor or graphics card, faster than the speed that has been determined by the manufacturer and hardware settings. Faster speeds are achieved by using a higher clock multiplier of faster bus speed. Often, voltages to the device must also be raised.

Overwrite

To write data on top of existing data, erasing the existing data.