How to control the jobs with shell?

There are 3 commands to contol jobs.

1. Ctrl + Z
2. bg & fg
3. kill
4. jobs

For example,

1. robert@debianlaptop:~$ emacs

[1]+  Stopped                 emacs

2. robert@debianlaptop:~$ fg %1
emacs

[1]+  Stopped                 emacs

. robert@debianlaptop:~$ bg %1
[1]+ emacs &

3. robert@debianlaptop:~$ jobs
[1]+  Running                 emacs &

4. robert@debianlaptop:~$ kill %1

 

The processes stopped by Ctrl + Z becom the jobs.