A warranty deed is a deed in which the grantor warrants good, clear title. It is a deed which explicitly contains covenants concerning the quality of title it conveys. Yes, it is a conveyance ("transfer") of title.
The short answer to your question is that a warranty fulfillment deed is the deed which would be given when a real estate contract was paid in full.
However, you shouldn't concern yourself with this issue. If you are going to buy property, get title insurance (Usually provided by the buyer). If it doesn't guarantee that you get clear title, don't buy the property.
There is no attorney client relationship between the persons who asked and answered this question. You should always consult an attorney for specific legal advice.
Think of it as kind of like a lien release. It is used in connection with another document known as a Real Estate Contract. It is somewhat comparable to selling your car on installments and holding the title. The Real Estate Contract is the evidence that you are buying/selling. The Fulfullment Deed is evidence that the Real Estate Contract has been paid in full ("fulfilled").