Hava alias shortcut available in new terminal session

To have your alias definitions available anytime, define them in your .bashrc file. It is a hidden file in your home directory, and is executed automatically each time you open a terminal.

Open that file with your text editor. A good place to add your own aliases is where some aliases are already defined. You will find a comment line: # some more ls aliases. There, you can add your own aliases. Save and close the file when done. From now on, your new aliases will be available in any new terminal.

If you maintain a lot of aliases, it is more practical to create a separate file with the name ~/.bash_aliases and put all your alias definitions there. Ubuntu is set up to automatically source an existing .bash_aliases file in .bashrc.