File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

GIF file extension

Graphical Interchange Format File

Raster Image Files

ZIP file extension

Zipped File

Compressed Files

MP3 file extension

MP3 Audio File

Audio Files

M4A file extension

MPEG-4 Audio File

Audio Files

AI file extension

Adobe Illustrator File

Vector Image Files

PRF file extension

Outlook Profile File

Settings Files

RSS file extension

Rich Site Summary

Web Files

LNK file extension

Windows File Shortcut

System Files

ISO file extension

Disc Image File

Disk Image Files

BIN file extension

Binary Disc Image

Disk Image Files

MDB file extension

Microsoft Access Database

Database Files

JAVA file extension

Java Source Code File

Developer Files

PART file extension

Partially Downloaded File

Misc Files

SAV file extension

Saved Game

Game Files

7Z file extension

7-Zip Compressed File

Compressed Files