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

DBF file extension

Database File

Database Files

DOC file extension

Microsoft Word Document

Text Files

DEB file extension

Debian Software Package

Compressed Files

7Z file extension

7-Zip Compressed File

Compressed Files

UUE file extension

Uuencoded File

Encoded Files

ROM file extension

N64 Game ROM File

Game Files

COM file extension

DOS Command File

Executable Files

CLASS file extension

Java Class File

Developer Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SH file extension

Bash Shell Script

Developer Files

ODT file extension

OpenDocument Text Document

Text Files

SQL file extension

Structured Query Language Data File

Database Files

AI file extension

Adobe Illustrator File

Vector Image Files

YUV file extension

YUV Encoded Image File

Raster Image Files