TAR, Consolidated Unix File Archive (.tar)
The TAR Archive file format
The TAR file format was developed primarily within an UNIX environment with the intention to sustain tape backup procedures. Afterward, it has been used for the purpose of file archiving and for the collection of multiple files into a single file for distribution or storage. TAR also refers to the application that handles TAR files.
Technical details of TAR files
Basically, TAR is a collection of files merged into a single file which is not compressed by default. The TAR file can be compressed by various compression applications available like GZIP. The extension of TAR file is changed to TAR.GZ after being compressed in such a way. Files with the TAR extension comprise of file data and a file header rounded up to a multiple of 512 bytes.