terminal sessions

I saw a presentation that involved working with the Mac terminal. What was interesting was that the guy opened several sessions in the same terminal window. It's like on Linux, you open a terminal and then in the same window you can open terminal no. 2, 3, etc..

What settings should I change in order to have the same functionality?

There are a couple of ways to achieve this on OS X. The first is to install iTerm, which is a Terminal.app replacement that supports 'tabbing'. This is a nice GUI way to do it.

The other way (that I prefer) is to use a program called 'screen' that, iirc, comes installed by default. Just type 'screen' at the command prompt and you will get ... a blank terminal window. Pressing Ctrl-A then ? will bring up a list of keystrokes or you could read a tutorial like this one.

My preferred program is screen because, with a simple press of ctrl-A then D, you can 'detach' it. This leaves everything running in the background and you can 'reconnect' it later by running 'screen -r'. This is how i manage to never log off IRC - I have a machine that I never shut down or put to sleep running screen. Whenever I want to use IRC, I use ssh to access the machine then screen -r to reconnect to the terminal where I left off, even if that's at another computer.