How to delete everything off my iphone?

My mother just got herself a new Iphone 5 and she gave me her Iphone 4.

We set up her phone and it has everything of hers on their. But everything of her stuff is on her old phone too and I want to wipe it clean so I can put my stuff on there.

is there a way I can wipe it clean and not wipe off her stuff on the Iphone 5?

Just search iphone factory research on Google.It'll explain how to delete everything.

Go to settings -->general-->scroll down until u find reset or erase--> erase all data