Okay now before we go on to populate this page with some of the file extensions, lets first see what exactly it is all about. File extensions are unique identification letters given to some files so as to indicate their type and sometimes even their contents. Some of the important file extensions are given below:

AR: Javasoft JRE 1.3 Library File

ARC: Archive

ASC: ASCII Text

ASP: Active Server Page

AUTOCONF: UNIX File

AVI: Audio Video Interleave file

BDF: X11 Bitmap Distribution Format

BIF: Binary Information File

BMF: BMF Bitmap

BPC: BuildPro File

BRS: Corel Painter Brush File

BRX: Multimedia Browsing Index

BUC: Photoshop Elements Backup File (Adobe Systems Inc.)

BUF: WinXL File

Bug: Bug (problem) File

CAB: Cabinet File (Microsoft Corp.)

CB: Clean Boot File (Microsoft)

CBL: COBOL Program

CCK: Corel Clipart Format (Corel)

CCX: CorelDraw File

CDB: Clipboard File

CDR: Sound File

CDT: CorelDraw Template (Corel)

CLS: Visual Basic Class Mode

CMD: DOS CP/M Command File

CMP: JPEG Bitmap

CMT: CorelDraw

COB: COBOL Program File

COM: Command

CONF: Linux Configuration File

CTC: PC Installer Control

DAO: Windows Registry Backup

DDT: Linux Configuration File

DIR: Directory Indicator (Microsoft)

DOC: Microsoft Document/Documentation

DOS: Network Driver File

EXE: Executable File (Microsoft)

GIF: Graphic Interchange Format

HIPS: Bitmap Graphic

HTML: Hypertext Markup Language

IDX: Index

IP: Internet Protocol

ISP: Internet Communication Settings

JAR: Java Archive Software

JPEG: JPEG/JIFF Image

KEY: Keyboard Definition File

MIME: Multi Purpose Internet Mail Extensions File

MP3: AlbumWrap Wrapped Music File Archive

MP4: MPEG-4 Video File

OGG: Ogg Vorbis Codec Compressed Multimedia File

OMF: Open Media Format File

RAR: WinRAR compressed Archive

SAT: Firefox Bookmark Backup File

SIS: Symbian OS Installer File

TFT: Text Formatter Plus Text File Information

These were just some of the many file extensions known, which helps the user to get a brief idea of the type of software he is downloading and whether or not the file is compatible with his system.