MAC
Media Access Control. A network protocol used to control the access to the network by different devices.

MAC Address
Media Access Control address (also hardware or physical address). Every device on the Local Area Network has an unique MAC address. It is used to identify devices and to control access to the network using MAC protocol.

Macromedia
This is the corporation which produces many of the world's most popular web authoring and desktop publishing softwares - including Dreamweaver, Flash, Freehand, etc.

Their official website is at http://www.macromedia.com

Mailing List Software
A mailing list is a discussion group based on the e-mail system. You may want to set one up - they're very useful promotional tools. Even if you don't want to host a discussion group, you can use a mailing-list program to distribute a newsletter.

Many companies have mailing-list software available for their clients to use -- if so, ask whether there's an additional cost, how many mailing lists you are allowed to have, and how many members per list

Mailserver
The Internet host (together with the appropriate software) that is used to send, receive and forward email messages.

Mainframe Computer
A powerful computer used for computing-intensive tasks.

MBps
MegaBytes (MB) per second, 1 MB = 1,048,576 bytes

Mbps
Megabits (Mb) per second, 1Mb = 1,048,576 bits

Megabyte
A million bytes. Actually, technically, 1024 kilobytes.

Memory
Refers to the RAM of a server.

MIDI
Musical Instrument Digital Interface -- A network and accompanying protocol developed in the 1970's for tranmitting various information between musical and other devices including keyboards, samplers, lights, controllers, etc.

MIME
Multipurpose Internet Mail Extensions. The standard for attaching non-text files to standard Internet mail messages. Non-text files include graphics, spreadsheets, formatted word-processor documents, sound files, etc. An email program is said to be MIME Compliant if it can both send and receive files using the MIME standard.

When non-text files are sent using the MIME standard they are converted (encoded) into text - although the resulting text is not really readable. Generally speaking the MIME standard is a way of specifying both the type of file being sent (e.g. a Quicktime™ video file), and the method that should be used to turn it back into its original form.

Besides email software, the MIME standard is also universally used by Web Servers to identify the files they are sending to Web Clients , in this way new file formats can be accommodated simply by updating the Browsers' list of pairs of MIME-Types and appropriate software for handling each type.

Mirror
Probably the most common use of the term on the Internet refers to 'mirror sites' which are web sites, or FTP sites that maintain exact copies of material originated at another location, usually in order to provide more widespread access to the resource.

Another common use of the term 'mirror' refers to an arrangement where information is written to more than one hard disk simultaneously, so that if one disk fails, the computer keeps on working without losing anything.

Mirrored Drives
Drive mirroring (also known as RAID) is the practice of duplicating data in separate hard drives to make storage more redundant. Mirroring provides data protection in the case of disk failure, because data is constantly updated to both disks.

Miva Empressa
Miva's XML based server-side scripting language. Available for multiple platforms. More information is available at http://www.miva.com/products/empresa/

Miva Merchant
Browser-based storefront development and management system for merchants. More information is available at http://www.miva.com/products/merchant/

Modem
MOdulator, DEModulator. A device that you connect to your computer and to a phone line, that allows the computer to talk to other computers through the phone system. Basically, modems do for computers what a telephone does for humans.

Modify (Domain Name)
The database that the TLD registries maintain need to be accurate in order for name resolution, billing, renewal notices and public records to be processed correctly. Typically modifications are required when nameservers need to change or the contacts change email or postal address or phone number. The procedures for modifying records will depend on the registry.

MOO
Mud, Object Oriented. One of several kinds of multi-user role-playing environments, so far only text-based.

Mosaic
The first WWW browser that was available for the Macintosh, Windows, and UNIX all with the same interface. Mosaic really started the popularity of the Web. The source-code to Mosaic has been licensed by several companies and there are several other pieces of software as good or better than Mosaic, most notably, Netscape.

MP3
An extremely popular lossy audio compression format. Widely used over the Internet.

MUD
Multi-User Dungeon or Dimension. A (usually text-based) multi-user simulation environment. Some are purely for fun and flirting, others are used for serious software development, or education purposes and all that lies in between.

A significant feature of most MUDs is that users can create things that stay after they leave and which other users can interact with in their absence, thus allowing a world to be built gradually and collectively.

Multicast
A message that is sent to a specific group of hosts.

Multimedia Streaming
Most web hosting plans with adaquate bandwidth allocations offer webmasters the option of streaming multimedia files (video and/or audio) from their websites. Common multimedia streaming formats include Windows Media (.wma), Quicktime (.mov), Real Audio (.ra), etc.

MUSE
Multi-User Simulated Environment. One kind of MUD - usually with little or no violence.

MX Record: Mail Exchange
Mail Exchange record is part of the zone file and is used to designate which mail server machine should process email for a specific domain.

MySQL
Most popular open-source relational database. Many Unix-based plans allow MySQL databases. A database allows for you to store information and then redisplay that information on a web page that is dynamically created.