We use alias in Unix to give a short name to a long command. We can even use it to combine multiple commands and give a short convenient name.
E.g. alias c=’clear’
With this alias we just need to type c for running clear command.
In bash we store alias in .bash_profile file.
To get the list of all active alias in a shell we can run the alias command without any argument on command line.
alias ki=’kill -9′