To create and keep aliases between sessions, you must save them in your shell configuration profile file. For bash, the path is ~/.bashrc.
The syntax is as follows:
$ alias shortName="really long name"
Here is an actual example:
$ alias ll="ls -alF"
So open your configuration file and add:
# You can comment with # btw
alias ll="ls -alF" # for example
alias ela="extLauncher" # another example
Save the file. The file will be automatically loaded in your next session. If you want to use the newly defined alias in the current session, use source:
$ source ~/.bashrc
source: