Welcome to the File Extension Database

Helping You Fix File Extension Errors

Your computer is filled with an alphabet soup of file extensions with strange names such as .dll, .m4a, .dcox, .widget, .bup, and .class just to name a few. In fact, the number of file extensions out there is mind-boggling. Just what exactly do these extensions mean and what are they for? First, programs are made up of files. For example, if you look in the Program Files section of your computer and select the folder for Microsoft Office, you will see hundreds of related files - all with various file extensions such as .dll and .exe. In addition to program files, your computer has system files which are usually hidden by default. These are files that your operating system needs in order to run properly. Some of these files are editable allowing users to customize certain system settings. However, minor keyboarding mistakes could lead to disastrous results. If in doubt, do not open or change system files. Another type of file is a data file. This is where information that you enter is stored. For example, if you use Microsoft Money for your banking, all of your account information and transactions will be stored in a data file.