Change of Address/Driver's license & Registration

Location: New Jersey

I just moved from Tennessee to New Jersey two weeks ago. New Jersey requires that I have to change my license and car registration within 60 days of moving or whenever my license/registration expires (whichever comes first). I fully intend to comply with this - I have no desire to break the law.

However, I am curious as to why this is the law and how it is enforced. Again, I'm not trying to flout this requirement. But Tennessee has no such stipulation (as far as I understand, perhaps I am wrong) so this is just an inquiry so as to educate myself.