A video format refers to the way video data is encoded and stored. It determines how the video is compressed, the quality of the image and sound, and how it can be played back on different devices. Common video formats include MP4, AVI, and MOV, each with its own advantages and compatibility with various platforms. Choosing the right video format is important for ensuring that videos can be easily shared and viewed. For example, MP4 is widely used for online streaming due to its balance of quality and file size, while AVI may offer higher quality but results in larger files.