A deed can transfer property to new owners, by gift, or by payment. Deeds have express & implied warranties, to ensure that a) the property has not already been transferred to someone else (A fraudulent situation where a seller is trying to collect payment on a title from 2 or more buyers) & b) if the property is free from any encumbrances. A special warranty deed only warrants things that occurred during their physical ownership; therefore, it does not guarantee against defects in title during or before they took possession of the property.
A deed establishes legal & equitable title, & ownership to a property. It represents the obligations owed to the buyer by the seller.