Your .bashrc might contain something like this:
alias ls='ls --color=auto'
This line defines an alias for the ls command, named ls. Weird? Not at all. Aliases override commands and builtins of the same name. The above example results in ls always displaying colorful directory listings, because Bash checks whether a word is an alias before looking for a builtin or command.
Another example: If you frequently ssh into boxes on your local network and start GUI programs on them, the following enables X forwarding by default.
alias ssh='ssh -X'
Aliases also work for programs that are started from the menu in a desktop environment. If you are over 25 and happen to like classical console games, meaning you probably have ZSNES installed, you can fix issues with missing audio using
alias zsnes='zsnes -ad sdl'
Add that to .bashrc, then log out and in and clicky-clicky on the icon.