Great question for Google. Something like "Drill bit guide" or "different types of drill bits".

Armed with a basic understanding of drill bits you can read the descriptions for DeWalts drill bits and apply what you've learned to make the best choice.

I could do this. Someone else probably will but I think you should do it. Research what you want to buy because we won't always have the answer. You'll remember it if you go through the research process yourself instead of just being told the answer. All those nerds spent a lot of time putting this information online for you. I think you can Google it. You're cluttering up the internet. Wasting pixels and electricity time my time now. In the time it would take to waste my time with a reply you could learn all about drill bits. If I never see you again I'll assume you did the smart thing.