Every computer user should know that the system has a huge number of all kinds of files that differ in type. In most cases, they are even graphically indicated by different icons. Let's see how the file type is associated with its extension and what information can be extracted from this.
What is a file extension?
First of all, you need to be clearly aware that the file extension did not come from somewhere from the ceiling. The file name extension, as a rule, characterizes its type, or rather, created by reducing the main description.
The simplest examples are, say, a file with the extension .exe (short for Executable or “executable” in Russian) or .wma (short for Windows Media Audio - sound type), etc. As you can see, the file name extension, as a rule, characterizes not only its type, but also its belonging to the main program, which is provided in the OS for opening it. Let's see how this is perceived by the system itself.
File name extension: what characterizes this reduction?
File types cannot be talked about without taking into account applications that are initially capable of opening them. True, and here it is not so simple. Look, after all, EXE files are essentially programs themselves and are designed to open other files.
In addition, with the help of executable components of the type .exe, you can directly open projects or documents created in this application, unless another program is matched (which is quite common). For example, documents that have the extension .doc (native Microsoft Word format) can be opened not only in a standard office application or in WordPad, but also in most third-party programs.
As for some program files, for example, dynamic .dll libraries (short for Dynamic Link Library), the file name extension, as a rule, characterizes that even though such a component is executable, it nevertheless contains executable code that can only be run when using system tools like the Rundll32 service.
Another example would be universal bank sounds (.fxb files). In this case, the file name extension characterizes only that it can be opened in any virtual synthesizer that supports this format. In other words, there is no single universal program for working with them, but any application capable of recognizing this type can be used.
File Type Recognition
As already mentioned, the file name extension, as a rule, characterizes not only its type (format), but also its belonging to a certain program with a default association. In the case when the association is set, the file is opened automatically.
Probably, everyone noticed that most of the files in the same "Explorer" are indicated by different icons indicating a matching present. Opening can be done by the usual double-click from the file manager menu or by using the corresponding command of the running application. In addition, you can always use the standard keyboard shortcut Ctrl + O, which is similar to the Open command.
Another thing is when in the system the file is not indicated by any icon. Of course, this does not mean that the system does not know what kind of data it is. It is very likely that you can open a file in several ways. That is why in such a situation several variants of programs can be offered, which, comparing the data in the file itself, select programs that are conditionally capable of working with this type.
However, let us return to the fact that the system still does not recognize a specific data type. Take a simple example: a .dmg file. In this case, we are dealing with a disk image, but! The file name extension, as a rule, characterizes only the moment that it was not created on Windows, but on Mac OS X. Naturally, there is simply no means to open this type of file in Windows initially. Even if you open the file (if you have certain programs, this can be done), it is still not possible to use the extracted information in the future (it just won’t work).
Conclusion
Here is a brief summary of all the file extensions. Note that this is a very brief overview, because if you look at the file types and formats themselves , there are so many of them today that it is simply not possible to describe them all separately, including opening methods.
The main thing is to understand that a file extension is a characteristic of its type (audio, video, graphic, text, etc.). It is formed by the abbreviation of the name, and also (in some cases) directly or indirectly indicates the method of opening or using some process to work with it.