MAC address: Short for Media Access Control address, a hardware address that uniquely identifies each node of a network.

malware: A type of application that is designed to cause problems (such as file corruption and stealing personal information) to computer systems.

managed cards: Digital information "cards" you send to trusted Web sites; they contain all the credit card and other personal identity information that you supply them in the course of doing business.

master file system: When burning CDs and DVDs, this setting allows the disc to be read by most computers and players, but it does restrict you to only adding files one time.

MBR (master boot record) partition: The portion of the hard drive that contains the operating system.

Media Extender: A piece of hardware used for making your media libraries accessible to non-computers on your home network, such as Xbox 360 and SmartMedia televisions.

Meeting Space: A Windows tool that lets you set up networks on the fly without a hub or a router by skipping among wireless cards.

memory: Temporary computer information storage which is emptied when you turn off the computer; also called RAM. The term "memory" also refers to the physical chips capable of holding data.

Messenger: A full-featured instant messaging tool — now a part of the Windows Live Essentials pack — that works with any version of Windows as well as Yahoo! messenger.

MHT: A Microsoft-proprietary “Web archive” file format.

Mobility Center: The Mobility Center contains all the main laptop settings: adjusting brightness, changing the sound volume, saving battery power, connecting to wireless networks, and setting up external displays or projectors.

modem: Modem is a contraction of modulator-demodulator. A device that converts digital data from a computer into analog data for transmission over telephone lines by modulating it into waves. At the other end, a modem converts the analog data back into digital form by demodulating it. Cable modems also convert data but that information may stay in digital form.

move: To change the location of a file, deleting the file from its original location.

Movie Maker: Microsoft's video-editing tool, which is now a part of the Windows Live Essentials pack.