| Extension | MP4 |
| Full Name | MPEG-4 |
| Type | Video |
| Mime Type | video/mp4 |
| Format | Binary |
An MP4 file is a modern standard format for storing high-quality motion video in a highly compact and efficient file size. The specific compression algorithm used within an MP4 file can vary from file to file; however, they all enable what would otherwise be a large amount of uncompressed data to be reduced to a fraction of the original size with little or no noticeable difference in playback quality.
Due to their widespread support, MP4 files can be loaded into most video editing applications and played with most video playback software with no additional drivers. Most video sharing sites, such as YouTube, support MP4 as a format when uploading, and most tablets and smart phones can record in the MP4 format.
Audio stored within an MP4 file is usually stored in the MP3 format, taking advantage of that format's high quality and compression capabilities.
| Extension | AVI |
| Full Name | Audio Video Interleave |
| Type | Video |
| Mime Type | video/x-msvideo |
| Format | Binary |
The AVI video file format is a general-purpose multimedia format for housing video and audio data. Created by Microsoft in the early 1990s, the format has, over the years, garnered widespread support; however, with more modern and capable formats such as MP4, AVI is now considered a legacy format, with support for it on the decline.
The format allows the storage of both audio and video tracks using a variety of different codes. This allowance for different codes means that some AVI files would not play on devices that did not have the correct codec software installed.
Despite AVI files being superseded by more efficient formats that offer improved codecs and other features, many video editing and playback software can open and play AVI files.
