If you look at the list of files on your computer, you can see that the filenames have two parts separated by a period. Obviously, the first part is the name of the file, but the second, the extension, most often consists of a seemingly meaningless set of letters.
Why extensions are needed
The extension is the same required attribute of any file as its name. The fact is that the operating system is not able to intuitively determine the correspondence of a file to a particular program by name. The file name extension is intended to give the operating system the ability to "understand" which program should process this file. In addition, from the point of view of the system, it is the extension that contains information about the file format and the actions that must be performed with it.
Today there are several thousand file formats and a comparable number of name extensions. Some extensions have traditionally been used almost from the very beginning of the spread of personal computers, for example, the.exe extension (from the English executable - executable), which denotes files that launch a particular program, while others have appeared quite recently. The fact is that many software products create auxiliary files for their work with unique extensions that no other program can recognize. And as more programs appear on the market, the number of extensions is growing every day. In addition, the number of file formats of various types is constantly growing: audio, graphic, video, and each of these formats needs its own extension.
The user does not need to remember all the file name extensions and programs associated with them. Most of the most common formats and extensions are automatically identified by the operating system, allowing the user not to think about which program to open a particular file.
Extension decryption
In modern operating systems with graphical shells, the recognized file extensions are often hidden, and the file format and the corresponding program are displayed with a specific icon. The problem is that the same program can correspond to several types of files, so sometimes it is more convenient to still enable the display of extensions. In the family of Windows operating systems, this can be done by selecting Control Panel from the Start button menu and then clicking on the Folder Options icon. In the "View" tab, you need to find the item "Hide extensions for registered file types" and uncheck it. All extensions will now be visible to you.
It can be difficult to decipher the meaning of a particular extension, especially if it was created for the auxiliary file format of a little-known program, but a list of the most popular name extensions can be found on the Internet. There are special sites that will not only tell you which program you need a file with the extension you are interested in, but also help you understand how the letters that make up the extension are deciphered. In the overwhelming majority of cases, the extension is either an abbreviation (for example, the extension of the popular.jpg"
