A file extension is a suffix added to the end of a filename to indicate the file’s format or type. File extensions are typically one to four characters long and are separated from the filename by a period (.). For example, the file “myfile.txt” has a file extension of “.txt”, which indicates that it is a text file.
File extensions are important because they allow computers to identify the type of file and open it with the appropriate program. For example, when you double-click on a file with a “.txt” extension, your computer will open it in a text editor. If you double-click on a file with a “.jpg” extension, your computer will open it in an image viewer.
