File sizes: The measure of the size of a computer file, usually measured in bytes (B), megabytes (MB), kilobytes (KB), and gigabytes (GB). Video, audio, photography and graphics can take up a large amount of space on a hard drive. A 1- hour MP4 video file can often be as large as 300 MB. Some video-file types, such as AVI, are better suited for recording but are too large for posting on the web. Other file types, such as MP4 and Adobe Flash, are more compressed and, therefore, better suited for web distribution and streaming. Camtasia Studio, Adobe Premiere and similar editing programs convert large file sizes to smaller sizes for sharing or posting to the web.