What do we need to store user input data such as name,surname and email?

I am new in web programming. I need to store user inputs. I have two text input and a send button. When the user clicks the button I want the infos is stored in xml or any other data storage tools. I have searched a lot for this but I'm confused and I don't have any exact idea what I need to do this. Can someone help me about this problem please?