A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the ...

A file extension is a suffix that is added to the end of a file name after a dot. It is usually two to four letters long. File extensions help Windows and other operating systems to know the standard ...

You're probably aware that most files have an extension such as TXT or EXE after the file name, even though these are not always displayed in Windows. File extensions are how Windows knows what to do ...

Microsoft hides file extensions in Windows by default even though it's a security risk that is commonly abused by phishing emails and malware distributors to trick people into opening malicious files.

While the launch services in OS X use file name extensions to associate files with various applications, generally users do not need to interact with these extensions and the system keeps them hidden ...