Butter can definitely be frozen and if you are not going to use the butter that you get home from the store immediately, it will be important to freeze it. Before you freeze your butter though you will need to run it under warm water for a few seconds, just so the wrapping comes off easily when you take it out of the freezer to use.
Keep in mind that butter that is kept in the refrigerator stays good for almost six months, but if you plan on keeping it longer than that you will probably want to think about freezing it. When you freeze your butter you will be able to preserve it for as long as you need to so it does not go back. A lot of people make the mistake of not properly storing their better and as a result they sometimes end up suffering from food poisoning. Just remember that keeping your butter in the fridge does not mean it will last forever. If you want it to last longer make sure you store it in the freezer.