You know this situation you started eclipse in a terminal and after opening a few files you want to type some commands in the terminal but you forgot the & after the command.
You can kill the programm (eclipse) with strg+c or you can pause it with strg+z and send it to the background with the bg command. After that your programm is continuing normal and you can use the terminal.
thomas@thinky ~ % eclipse
^Z
[1] + 5497 suspended eclipse
20 thomas@thinky ~ % bg
[1] + 5497 continued eclipse
thomas@thinky ~ %