Use fg to move a job from the background into the the foreground. By default fg works on the most recent background job.
Example…
Bring the most recent background job into the foreground…
$ fg <Enter>
To specifiy a job to move into the foreground when you have many jobs in the background give the job number preceded with a (%) as an option to fg.
Example…
Bring job 4 to the foreground type…
$ fg %4 <Enter>