split CLI terminal
 

is it possible to split/divide CLI terminal into two parts so that i can do two different works without switching to other tty, and i can see those two windows simultaneously.

If you mean using x-windows, then yes. You can open 2 terminal windows or one terminal window with 2 tabs. Konsole does this and I'm sure most of the other terminal programs let you do that.
cheers,
jdk

i m not using xterm,i waana do this with Command line Interface (virtual terminal, the black screen), can i?

Check out screen, it is the most popular virtual terminal multiplexer.

Yes, screen would be the one to use in this case. There's also splitvt, which has a small subset of screeen's features, if screen seems a bit intimidating at first.

Gnu screen go e you other great features as well. You get the ability to share your screen with others as well as detach and reatach latter. This is great for starting something at work then heading home and checking on it later.