Shell commands from vim
You can start a shell from Vim using the :sh command. When the shell exits(after the exit command or Ctrl+D) you return to Vim. The name for the shell command comes from the shell option.
For terminal Vim (on unix-like systems) you can also use Ctrl+Z to suspend Vim and get back to the shell from which it was run. To resume the Vim process, use the fg command.