ALT File extensions are crucial for identifying the types of files we use on our computers. Text files, such as .DOC, .PDF, and .TXT, are used for documents and written content. Compression files, like .ZIP and .RAR, help in reducing the size of files for storage or transfer. Video files come in formats such as .AVI and .MP4, while audio files include .WAV and .MP3, catering to multimedia needs. Executable files, including .EXE and .CMD, run programs and scripts. Lastly, image files, such as .JPG and .PNG, are used for pictures and graphics. Each file extension serves a specific purpose, making it easier to manage and organize digital information.