Resuming execution of a suspended console process in the background

~$: ./start_a_testscript
Script is running fine in the foreground.

Press Strg+Z

~$: bg

bg resumes the execution of the suspended (Strg+Z) process without bringing it to the foreground.

fg is the complementary command and resumes the execution of the suspended (Strg+Z) process bringing it to the foreground.