Technology Computer Terms and Acronyms M through O
Computer Terms - Letters M through O
MAC (media access control) address: unique 6-byte address associated with and coded into each network interface card (NIC); address assignment is controlled by the IEEE
MAN (metropolitan area network): connects sites in and around a large city
MB (megabyte): unit of information or computer storage equal to either exactly one million bytes or, in some cases, 1,048,567 bytes, or more rarely, 1,024,000 bytes; not to be confused with Mb, which stands for megabits
Mbps (megabits per second): a unit of information storage; not to be confused with MB or megabytes
Medium: transmission, or system that carries the message or data
MAU (medium attachment unit): converts signals on an Ethernet cable to and from AUI signals
Memory: desk space of the computer system; microchips located on the motherboard that hold data and instructions for the CPU (central processing unit)
Memory management: allocates memory to separate tasks and protects data from corruption
Menu: used in some DOS shells and early versions of Windows; an improvement on the command line but cumbersome when a task requires the submenu of a submenu of a submenu of a menu item
Message: information content to be shared
MHz (megahertz): one hertz is one cycle per second; a megahertz is equal to one million cycles per second
MIB (management information base): a type of database used to manage the devices in a communications network
MPEG (Motion Picture Experts Group): digital video format identified by .mpg extension after the file name; a working group of ISO/IEC charged with the development of video and audio encoding standards; pronounced m-peg
MPLS (multiprotocol label switching): an initiative that integrates Layer 2 information about network links (bandwidth, latency, utilization) into Layer 3 (IP) within a particular autonomous system to simplify and improve IP packet exchange
Mpps (millions of packets per second): a measurement of information sent per second
Multiplexing: process of putting multiple signals on a wire simultaneously
Multiport repeaters: allow multiple devices to be wired to a central location, share the same media, and regenerate (repeat) the signal; also referred to as active hubs
Multitasking routines: permit two or more distinct tasks to be performed concurrently by the computer
Name resolution: process by which the peer-to-peer name used on each conversational level is related to other levels
NAP (network access point): transitional data communications facilities at which Network Service Providers (NSPs) would exchange traffic, in replacement of the publicly-financed NSFNet Internet backbone; now replaced by modern IXPs
NAT (network address translator): involves re-writing the source and/or destination addresses of IP packets as they pass through a router or firewall; also called network masquerading, native address translation, or IP-masquerading
NetBIOS (network basic input/output system): allows applications on separate computers to communicate over a local area network (LAN)
Network access layer: allows a computer to exchange data with another computer over a common network medium; part of the TCP/IP model that performs the same functions as the data link and physical layers of the OSI model
Network address: part of an IP address that is uniquely assigned by one of the ICANN-sanctioned agencies
Network design: how the various clients and servers are arranged for purposes of connectivity, performance, and security
NOS (network operating system): optimizes the client/server architecture; provides and supports network services such as file services, e-mail, Internet and intranet services, and applications
NIC (network interface card): hardware adapter that provides communication capabilities; responsible for building, transmitting, receiving, and decoding frames in a LAN environment; serves as the interface between the networked devices and the connecting wires
NNTP (network news transfer protocol): makes USENET possible; protocol for the distribution, inquiry, retrieval, and posting of news articles using a reliable stream-based transmission of news among the ARPAInternet community
Nonvolatile memory: chips that hold information even when the system is turned off
NRZ-L (non-return to zero level): form of digital encoding; negative voltage is used to represent a binary 1, and a positive voltage is used to represent a binary 0
NSP (network service provider): a business or organization that sells bandwidth or network access by providing direct backbone access to the Internet, and usually access to its network access points (see NAP)
OC1 (optical carrier, level 1): a fiber optic connection capable of transferring data at 51.85 Mbps
Operating environment: how the OS controls the hardware and application programs
OS (operating system): interface between the application (word processor, spreadsheet, etc.) and the computer hardware
OSI (open systems interconnection) model: developed to provide a view of the distinct functionalities that are required to implement each protocol layer; defines a complete range of functions that can be achieved with data communications equipment
OSPF (open shortest path first): a link-state hierarchical interior gateway protocol (see IGP) for network routing protocol

