Say for example that you're doing some tuning or modifying on the server and your using some comon commands, then to make things easy for yourself you could set up temporary aliases -(keyboard shortcuts) that you can use to speed up your work in ssh, insteading of having to type everything out again and again.
First open up a session in ssh
Now here are some common aliases that you could use
# to open up and edit your httpd.conf file
alias th='nano /etc/httpd/conf/httpd.conf'
#testing your apache configuration
alias te='service httpd configtest'
#to start
alias st='service httpd restart'
to remove an alias , type unalias th
where th is the alias you have set
All aliases are temp commands that get removed when you have logged out.