#extract
tar -xvf file.tar
tar -xvf file.tar -C /mzdir
tar -xvzf file.tar.gz

x: This tells tar to extract the files.
z: uncompress the file (gzip).
v: verbose

f: This options tells tar that you are going to give it a file name to work with.

# dtrx
dtrx stands for “Do The Right Extraction.” It's a tool for Unix-like systems that takes all the hassle out of extracting archives.

$ dtrx linux-3.0.1.tar.bz2

That's basically the same thing as:
$ tar -jxf linux-3.0.1.tar.bz2