it is used to place foreground jobs in background
$ bg
job number 1 is resumed
bg %1
lists all the jobs runniing in the background
$ bg jobs -l
runs the calculator app in the background
$run calculator &
to stop job pid 6517 kill commannd is used
$ kill -s 6517
to rsume stopped calculator
$ bg jobs -l
$ bg %calculator &
to rsume stopped calculator
$ bg jobs -l
$ bg %calculator &
to find bg is a part of shell or extrnal command or both of them
$ type -a bg
gives the commands to be used
$ help bg
job id 1 is stopped
$ bg kill -s stop %1