UNZIP

BZ files , tar -xjf <Filename>
GZ files, tar -xzf<Filename>
ZIP

tar -zcvf archive_name.tar.gz directory_to_compress

Zip Command

To compress:

zip squash.zip file1 file2 file3

or to zip a directory

zip -r squash.zip dir1

To uncompress:

unzip squash.zip

this unzips it in your current working directory.