Why does my iPhone 4s keep freezing?

My iPhone 4s that I have had for a little under a year now, keeps freezing on me and I don't know why. Whenever I try to open an app such as Facebook, Twitter, YouTube, my games, etc. My whole entire phone freezes for a couple of minutes if not longer. I try to shut it down and then turn it back on again, but it won't even let me do that, it stays on the same page that I was opened on. Could my iPhone 4s be corrupted? Or could this be some rare strange virus thing? Please help, I'm kinda nervous, I don't want it to be broken.

How full is your phone, do you have a lot of apps and is it jailbrroken? I would do a full reset of phone and settings. Back up important data first. You will lose all downloaded apps, but one of them could be the problem. You will need to re download them, you may have a restore on itunes that is before the problem started.