Learning Linux Shell Scripting - Second Edition

Command1 & command2

The first command is started in the background to continue until it has finished; immediately after starting the first command, the second command is started and it will run in the foreground:

    $ find / -name "*.z" & ls
    ----------------     -----
    Command1            command2

In the preceding example, the first command, find, will start running in the background and, while the find command is running in the background, the ls command will start running in the foreground.