Tar is a black, oily liquid with a characteristic odour obtained by the distillation of coal, wood and bituminous minerals. Tar varies in composition according to its source, but all kinds consist largely of hydrocarbons and contain suspended carbon, to which the black colour is due. By subjecting tar to distillation various constituents are separated and are employed as the raw material for making aniline dyes. The solid and brittle mass left after distillation is known as pitch. Tar has been used medicine in the treatment of skin diseases since at least the start of the 20th century.
In computing, tar is the name of the Unix tape archiver program. Files compressed with tar are recognisable by the extension '.tar' or '.tgz'. The contents of the archive may be extracted in various ways. If the archive file has the extension .tar, then the command line 'tar -xvf filename.tar' will work. If the file has the extension '.tgz' or '.tar.gz' then it has also been 'zipped' and the command 'tar -xzvf filename.tar.gz' or 'tar -xzvf filename.tgz' will extract the contents. The contents of an archive may be listed by replacing the parameter letter 'x' with 't' such as 'tar -tvf filename.tar'. Research Tar
Abbreviations
SciTech
Research Tar