How can I switch back normal mode from sudo mode in Linux and Mac OS X?

I use sudo su command to do something in Mac OS X but don't know how to switch back.

Hope you guy can do me a favour.

Type exit. This will logout the super user and go back to your account.

If you run sudo su, that will open a shell as the superuser. Type exit or Ctrl-D to exit this shell.

Normally, you don't run sudo su, but you just run sudo command. Once you type your password, sudo will record a timestamp and let you run more commands under sudo without having to type your password for a few minutes. If you want to clear that timestamp (so that someone else can't run sudo without a password), you can run sudo -k.

su is used to login into the root account, to logout from this , use Ctrl+D or type exit. Playing with su is very dangerous if not really necessary. The better idea is to add the used into sudo group and use the sudo command. And how come you use sudo su??