In operating systems such as UNIX/Linux or Windows it refers to the suffix of a file name, usually letters and or/numbers after a period. It is used as a way to identify the file type (the format and content type of a file), such as an executable file, program data, picture, video, audio, or document. Different file systems enforce different rules on how extensions are used. Some systems don't require extensions at all. Extensions are common mostly out habit and are still useful to quickly identify files in a list.
It tells you the format of the file. For ex. if a file is named xxx.ppt, this tells that the file is a powerpoint file. If the extension is changed, the file gets unusable. In the same way we have doc/docx (for WORD files), xls(for excels), txt(for notepad files), exe(for any programs)
In windows xp
the extension for a folder is generally
.FOLDER
it can be seen in the windows registry !!
Folders have no extension.
Keep an eye on your spam folder.
A compressed folder can have many extensions. The usual windows extension is .zip. But .7z (for 7zip) and .rar can also be used.
In nokia mobiles renaming file or folder name with an extension (z.otb) we can hide
.FOLDER but you can't turn a file into a folder by just adding above mentioned extension at end of any file. but it's surely possible with any programming language. Folders are a part of Windows Explorer unlike files.
all data is generally stored in a single file with a pst-extension
.zip .rar .cab
You can make new folder named mp3.Then you can place your song files of extension .mp3 .The folder is required to be made in the folder of the game.
c:\widows\system32\driverstore
rename one of the files
Right click on the app, then click Get Info. Under "Name & Extension" just remove the .app extension on the end and you should be good to go.
To Create a New File Extension File Association or Edit a currently existing one:1. Open any Folder (e.g. My Documents or a random folder)2. Click on Tools then Folder Options3. Click on the File Types tabA. To Create a New File Extension Click NewB. Enter the new file extension Then click Advanced and select the program to open the type of file with.A. To Edit a File Extension Click on the File you want to change in the scroll list.B. Click Edit and change settings to your wanted option.Hope this Helped :D