Yes, there is a difference between an agent and a broker. The roles of each are usually defined by state law and can vary from state to state, and since I'm not licensed in IA I can't give you specifics on the differences in your state. However, here is a link to an article which gives a good general overview of the distinction between the two.
I hope this has been helpful, and congratulations on the purchase of your first home.
I am licensed in the State of Ohio, posting a response to your question or issue does not create an attorney-client relationship and I AM NOT providing you legal advice. You should speak with an attorney who is licensed in your state to whom you have provided all the facts, before you take steps that may impact your legal rights--or rights to recovery of damages.