We encounter text files (documents) almost daily. However, in this matter, the extension of the text file and the text format of the data should not be confused, these are two different things. Let’s try to determine what files of this type are and what they are.
Text file extension: what is it?
To begin with, as a rule, most files of this type have an extension in the form of three letters after the separator (period). The simplest and most common type is files with the .txt extension, which can be opened on the same Windows systems using the standard Notepad.
However, despite the generally accepted rules, text document file extensions can contain not three letters, but more (their number can reach twelve, but not more), for example, electronic book files .djvu. In addition, numbers may be present in the extension.
What gives us a consideration of the classification of a text file (document) in terms of their identification? And the fact that one glance allows you to instantly solve an important question: what extension do text files have, such is the program mapped by it for opening or editing. Here, in many cases, it is almost always possible to determine the original application in which such a file was created.
However, do not forget that today you can find a fairly large number of files with the same extensions, but created in other applications or mapped to different programs. It would seem that a regular file with the extension .doc (.docx) initially corresponds to the text editor Microsoft Word. But you can open it or save it in this form in another word processor even on "apple" computers. This may also include a mixed type, so to speak - files in .pdf format, which contain not only text but also graphics. But Word documents can also contain embedded images.
It is this that serves as an indicator that the extension of the text file indicates the universality of the format itself, which is the most “readable” regardless of the operating system used. The same goes for text editors of any type.
Types of file extensions: text
In general, today there is such a huge number of text formats and their extensions that, probably, almost no specialist will undertake to calculate their total number.
Yes, of course, the universality of such documents is beyond doubt, especially if they use the simplest ASCII encoding. But sometimes the problem may be that not every encoding is supported by a particular system or program. That is why a set of characters appears on the screen instead of the usual letters.
As for the varieties of text files, you can’t list them all. The most common are the following: .txt, .doc, .tex, .text, .pdf, .log, .apt, .ttf, .err, .sub, .djvu, .odt, .rtf and many others. This list goes on and on.
Most interestingly, many files of this type have a different role in the system. For example, in addition to the usual .sub subtitle file, a plain text .txt document may be responsible for watching them when opening a video, and in this regard many formats are interchangeable.
Note that even executable files can have text as content. The simplest example is a .bat file created in a regular Notepad and containing text as a set of commands. At startup, commands are executed, and the menu “Open with ...” is used for editing, unless another action is initially associated with this process.
A similar situation is observed with documents that use markup or programming languages, say .html, .htm, .xml files, etc. Even web pages can be opened in many editors initially as text files containing third-party elements.
Change text file extensions
As for changing the extension, sometimes it can be changed, for example, .txt in .doc and vice versa. Word Editor will open any type. The same applies to the .txt - .bat pair when opened in Notepad. But in other cases, it’s better not to perform such manipulations, it simply will not lead to anything, and the renamed file will not be able to open another application. Changing the format will have to be done using special converter programs.
Instead of an afterword
As already understood, the text file extension can have many variations, depending on which program the document was created in. But, as in other cases, by the extension itself, it is almost always possible to determine the application that was originally associated with it, in extreme cases, open it with any other program that supports working with this type of data, even if the original application is not available on the computer. And as you probably already understand, it is text files that, in fact, are the most common and universal in the computer world, regardless of the software packages and operating systems used.