Which file extension is commonly used for video delivery and streaming?

• A. mov
• B. mp4
• C. avi
• D. mkv

Answer: (B)

Video delivery and streaming benefit from a format that is universally supported, efficient, and easy to stream. MP4 fits that need because the MP4 container (MPEG-4 Part 14) is widely compatible across browsers, devices, and streaming platforms. It supports progressive playback, so users can start watching before the entire file downloads, and it works smoothly with modern streaming workflows that use adaptive bitrate delivery (like HLS or MPEG-DASH) when paired with appropriate encodings. This combination of broad compatibility and streaming-friendly features makes MP4 the standard choice for delivering video online.

Other common formats are more tied to specific workflows or ecosystems. MOV is common in editing and Apple environments but isn’t as universally supported for web streaming. AVI is older and less efficient for streaming due to larger sizes and compatibility issues. MKV is feature-rich and great for local playback, but it isn’t as widely supported by web players and devices for seamless streaming.