File extensions can range from 1 letter to 7 letters.
For example ".A" used with Unix library or ".TORRENT" which stores metadata used for BitTorrent, and even double file extensions such as ".TAR.GZ" formed when a ".TAR" is compressed with a ".gzip".
No, folders usually do not have file extensions, but they could have if you like. Usually only files have extensions, to indicate the contents of the file.
There are no set file extensions for an ASCII text file, however one that is commonly used is .txt
Windows hides file extensions in File Explorer by default for known file types to simplify the user experience and reduce clutter. This setting can be adjusted in the Folder Options menu, where users can choose to show file extensions for all files. The option is typically turned on for security reasons, as displaying extensions can help users identify potentially harmful files. To view file extensions, users can enable the "File name extensions" checkbox in the "View" tab of the Ribbon in File Explorer.
Rules for file extensions are based mainly on the underlying operating system and/or file system. Generally speaking, file extensions are just a part of the file name, and can be set to whatever you like.
What do file extensions like avi, dv, dvd, mpeg mean?
For windows, you might use .cmd, .bat as common file extensions. Unix doesn't use file extensions as associations, so no file extension needs to be used in the Unix environment. A shell script in Unix is simply a text file with any name that is readable and executable. However, file extensions are typically used in Unix as a documentation aid that states that the file is a shell script. Common extensions are .sh, .csh, .ksh, .tcsh, .zsh, etc.
File extensions tell the computer what kind of program was used to create it, and are usually three letters. Common file extensions are .txt .doc .wps
File extensions are still necessary on Windows. They are no longer limited to three characters on FAT32 and NTFS file systems, though most system files were named with three character extensions in case someone wanted to use FAT16, and many are still named this way for backwards-compatibility purposes.
Different file types have different file extensions. This is the three letters, after the dot in the file name. eg. *.exe is an executable file *.doc is a document file, used by windows Word. *.txt is a text file, opened by various word processors or notepad. Windows keeps a list of known file extensions and open the appropiate program when the file is clicked on. If windows does not know what to use to open it, it will have a generic icon and will prompt you for a program to open it, when you click on it. Be aware that Windows can hide the file extensions, so you won't be able to see it in file lists. You can change this. In explorer, click on 'tools' at the top of the window, then 'folder options', then 'view'. Down the list, you will see a tick box that hides known file extensions. Un-tick it, to see extensions in file lists. On the next tab 'File Types', you can see a list of all the know file extensions and the programs they are associated with.
A file extension is a three character designation that tells software about the format of the data within the file. For example, a ".rtf" file is in rich text format which requires a word processor for it to be interpreted and a ".pdf" file is in portable document format (which requires Adobe Acrobat to interpret).A file extension is used in some operating systems to identify the type of the contents of the file. It is usually separated from the main part of the file name by a ".", but some operating system have used different characters.Most file extensions today are 3 characters long (e.g. txt, exe, jpg, mpg), but different operating systems have used file extensions as short as 2 characters to as long as 80 characters.Some operating systems do not make use of file extensions. For example Unix makes no use of them at all. VMS and the original MacOS used a file type field in the directory entry instead of file extensions.
File extensions for web pages usually are .html.
.edb file and .stm file