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

MPA file extension

MPEG-2 Audio File

Audio Files

FLA file extension

Adobe Flash Animation

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

JAVA file extension

Java Source Code File

Developer Files

INI file extension

Windows Initialization File

Settings Files

ASPX file extension

Active Server Page Extended File

Web Files

MDB file extension

Microsoft Access Database

Database Files

GZ file extension

Gnu Zipped Archive

Compressed Files

TORRENT file extension

BitTorrent File

Misc Files

SDF file extension

Standard Data File

Data Files

EPUB file extension

Open eBook File

eBook Files

TXT file extension

Plain Text File

Text Files

SH file extension

Bash Shell Script

Developer Files

CSV file extension

Comma Separated Values File

Data Files

XCODEPROJ file extension

Xcode Project

Developer Files