There are lots of archive types:
zip is most commonly used and the simplest archive format
rar is a good format used mostly on windows
There are also many other archive formats, like:
tar - it just packs lots of files into single file, referred to as tarball
tar.gz - tarball compressed using GNU zip
tar.bz2 - tarball compressed using bzip2
tar.lzma - tarball compressed using lzma
7z - archive format used by 7zip
The best choice for most stuff is 7z, or tar.bz2. rar is a bit doubtful since only packer/unpacker for windows is non-free.
There are no set file extensions for an ASCII text file, however one that is commonly used is .txt
Similar question has been answered here:What_is_the_file_extension_for_Microsoft_excel_file
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".
A compressed folder can have many extensions. The usual windows extension is .zip. But .7z (for 7zip) and .rar can also be used.
By default, Windows hides the extensions of files when viewed in Windows Explorer and on the Windows desktop. You may unhide all known file types by opening Windows Explorer, selecting Tools > Folder Options, clicking the View tab, and removing the checkmark to ñhide file extensions for known files types.î
If you don't see your extensions, this is because by default XP hides them (stupid if you ask me). In Windows Explorer (not IE) go to Tools|Folder Options... and in the "View" tab, uncheck "Hide extensions for known file types." Then you can change it just by renaming the file.
The default file extension for notepad is .txt. However, you can designate notepad as the primary application for any extension.
.txt is not a compressed file.
.txt is not a compressed file.
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.
By default, Windows hides the extensions of files when viewed in Windows Explorer and on the Windows desktop. You may unhide all known file types by opening Windows Explorer, selecting Tools > Folder Options, clicking the View tab, and removing the checkmark to ñhide file extensions for known files types.î
default program is an application that opens a file when you double-click it. For example, if you double-click a .TXT file in Windows and it automatically opens in Notepad, then Notepad is the default program for files with a ".txt" extension. If the file opens in Microsoft Word, then Microsoft Word is the default program. Default programs are necessary since many file types can be opened by more than one program. For example, your computer may have over a dozen applications that can open .JPG files. Therefore, theoperating system needs to know which program to open by default when you double-click a JPEG image file. Both Windows and Macintosh computers store a list of default programs for each file extension. These relationships between programs and file extensions are also called "file associations." Both the Windows and Macintosh operating systems allow you to change file associations if you don't like the default program that is associated with a certain file type. For example, if you prefer to play MP3 files in iTunes rather than Windows Media Player, you can change the ".mp3" file association to iTunes. This will set iTunes as the default program for all .MP3 files. Windows 7 has a built-in utility for configuring file associations called "Default Programs." This tool allows you to assign specific programs to one or more file extensions using a simple graphical interface. It also displays what file extensions are associated with each installed application. For more information on using the Windows 7 Default Programs tool, view theFileInfo.com Default Programs Help Article. While Mac OS X does not include a Default Programs tool, you can simply right-click a file and choose "Open With…" to select a different program to open it. If you want to change the default program for a specific file, select the file and choose File → Get Info. Then select a different program in the "Open with:" section of the window. If you want to change the default program for all files with the same extension, press the "Change All…" button