answersLogoWhite

0

Computer files have extensions. These are the part of the filename after the dot (the period). They are used to provide information about the file. Microsoft document files have a .doc extension. Text files are .txt. One kind of picture file is .jpg

These extensions let programs know if the file will work with them. If you try to put a file in a program that is unable to use/read/understand the file it may show a message saying, "This is not a valid extension," meaning I don't understand this kind of file.

User Avatar

Wiki User

16y ago

What else can I help you with?