tar is an archive tool.
bzip2 is a compression tool.
bzip yields great compression rate. (10%~15%)
These two programs above have executable support under Windows. Better set the environment variable "Path" so the commands "tar" and "bzip" can be easily called under command prompt.
first, tar the file, for example,
tar -cvf output.tar outputFolder
this will produce output.tar using outputFolder
then, bzip the output.tar (our tarball), for example