Actions are just shortcuts for the editing process. Just think of all the steps it takes to make a photo better. Well, Actions are installed and with the click of a button all can be done at one time.
There are several places to purchase/download them (free ones too). I LOVE working with actions.
Not sure if there is anything for other programs though.
You can get an idea from this site (of what certain actions can do) http://www.mcpactions.com/