What is the difference between a political action committee and a 527?

First of all a 527 organization seems to be a more broad definition, because a PAC is a form of a 527 organization. Also a PAC has more regulations from the government about the amount of money spent per candidate per election and things of that nature, while from my research I could not really find the same stipulations for just a basic 527 organization. Another thing that makes the two different is that the money from a PAC goes directly to the candidates while money from a 527 organization does not go directly go directly to the candidate.