I'm developing a web site in php in localhost and as modules of it gets completed, I upload it on the cloud so that my friends can alpha test it.

As I keep developing, I've lots of files and I lose track of which file I've edited or changed etc. I've heard of something as 'version control' to manage all those but am not sure how it works.

So, my question is: Is there an easy way/service/application available to me to track all the edits/changes/new files and manage the files as I develop the website. As Soon as I'm done with a module, I want to upload it on the cloud (I'm using Amazon Cloud Service). If something happens to the new files, I might want to get back to the old file. And maybe, in a click or two, I get to see the files which I've edited or changed since the last one I've uploaded?