Vim has an inbuilt terminal, which you can start with :terminal. That means that you don’t have to leave your Vim editor to run commands in the shell.
Sometimes, it’s still useful.
If you quickly want to switch to your shell, suspend the Vim editor with Ctrl+z. That sends the process into the background (on Linux).
Now you have access to your standard terminal and can run commands.
Type jobs or jobs -l to see a list of the background processes.
Type fg to bring the last background process into the foreground (“re-open” Vim). Or type fg %<number> to resume a different process with the id <number>.
The commands are part of bash. They are called job control (Linux).