Megabyte (MB) – A multiple of the unit ‘byte’ for digital information, used to quantify computer memory or storage capacity equal to 1,000 kilobytes (or technically, 2^20 = 1,048,576 bytes). For the purposes of this document, this measure relates to creative file size. (See definition for Byte)

Minification – The practice of removing unnecessary characters from code to reduce its size, removing unnecessary spacing, and optimizing the CSS code; thus improving load times.

moov atom – A video data object in a media file used to execute the video. The moov (or movie) atom should be placed at the beginning of a video file to ensure proper execution.

Mouse-off – The act of a user moving the cursor away (off) from the hot spot of an ad. Mouse-off by a user may trigger an event, such as collapsing an expanding panel or stopping any animation in progress.

Mouse-over – The act of a user moving the cursor and resting it on the hot spot of an ad for at least one second. Mouse-over may trigger an event such as expanding the ad or initiating an animated sequence within the ad. Mouse-over may NOT initiate audio play.

MP4 -A digital multimedia format used to store video and audio, but may also include features such as subtitles, chapter details, and other data related to the video or audio file. The filename extension for MPEG-4 files is .mp4.

MPEG – A set of standards for audio and video compression and transmission established by the Moving Picture Experts Group.

MPEG-DASH – An acronym for MPEG Dynamic Adaptive Streaming over HTTP. This adaptive streaming technique allows for a streaming experience using progressive download of several small chunks of video at different bitrates. An HTTP-connected video player (the client) detects the bandwidth at each chunk of time (about 3-5 seconds) and determines which quality level to download and play for the small duration allotted.

MRAID – An acronym for Mobile Rich Media Ad Interface Definition. MRAID is a protocol that enables communication between an ad and a mobile application in order to execute interactions such as geolocation, ad resizing, and accelerometer functions among others.