Do the fans regularly kick in on a MB Air?

Currently I am a student that is majoring in information systems. I am learning how to code in java. I am using eclipse to write my code but lately I have noticed that my fans have started kicking in more often lately. The fans not only come on when I am coding, but really just whenever I do anything. I own a baseline 2012 13" MacBook Air. Is it because of eclipse or could it be something else? I really don't do anything heavy on my computer. All I really do is write papers, code, Netflix and YouTube. Any help would be appreciated!