Use screen when you want to manage multiple sessions in a terminal. Install it on Ubuntu
sudo apt-get install screen
There are a lot of options for screen. I won't go into them. I use screen most often when I shell into a remote server and want to hop into my database, or parse a log file, run top and need to run another process at the same time. Instead of opening another terminal session, I just use screen and bypass login/sudo or whatever other options I have configured for my current terminal session.
Start up screen:
Create a new screen session
Tab between your screen sessions:
There is a whole lot more to screen, like assignment of sessions to other users and groups.