There are certain types of files that particular programs work with. These files have particular extensions which are the letters after the full stop in the name of a file, like help.txt. In this example, the extension is “.txt”. There are some many of these extensions that it is hard to keep track of what they stand for and which programs they can be viewed in or opened with. “Knowledge is power” and so it is always good to know what they mean or stand for.

Here is a list of some common file extensions that you are bound to encounter from time to time:

.txt - Text file that can be opened by any text editor
.pdf - Portable Document Format that can be opened using Adobe Reader
.doc - Microsoft Word document file
.xls - Microsoft Excel file
.ppt - Microsoft Powerpoint file
.db - Database file
.com - Command file (can be run as a stand alone file)
.exe - Executable file (can be run as a stand alone file)
.js - Javascript file
.zip - ZIP compressed file which is usually opened by WinZip
.rar - RAR compressed file which is usually opened by WinRAR
.hlp - Help file
.sys - System file
.pub - Microsoft Publisher file
.bat - Batch file (DOS file format) that contains the order in which commands are executed

There are thousands of file extensions. Many are designed specifically for particular programs and software. You can look for more file extensions using a search engine. I hope the information I provided was however of some help to you.