Deeds differ by how much the grantor promises
Every deed moves whatever title the grantor holds. What separates the types is the size of the promise attached: how far back in the chain the grantor will stand behind the title, and whether he warrants anything at all. Match the promise to the situation and these questions answer themselves.
General warranty deed
The general warranty deed warrants title against the claims of all persons and gives the buyer the broadest protection available. In Georgia that general warranty includes covenants of a right to sell, of quiet enjoyment, and of freedom from encumbrances. The warranty reaches back through the entire chain of title, not just the grantor's own years of ownership.
Special (limited) warranty deed
A special or limited warranty deed warrants only against defects arising during the grantor's own period of ownership. The word "special" is the trap: it sounds stronger than "general" but covers far less. It is the standard instrument in Georgia for fiduciaries, for lenders selling REO after foreclosure, and for builders.
Quitclaim and bargain and sale
A quitclaim deed conveys whatever interest the grantor has, if any, with no warranties whatsoever. That makes it the standard tool for clearing a cloud on title, such as a remote heir's doubtful claim, because no such claimant would ever agree to warrant the whole chain. A bargain and sale deed carries only an implied representation of ownership and no express warranties. An executor's deed is narrower still: it applies only to a personal representative conveying estate property.
The Georgia security deed
Georgia rule: the security deed, not a mortgage, secures Georgia home loans. It passes title of the property to the lender until the debt is fully paid, and is not held to be a mortgage. Georgia is a title-theory state. Saying the instrument creates only a lien leaving full title in the borrower states lien theory, the single most common error here. Foreclosure is non-judicial under the power of sale, not by a judicial action in superior court, and no separate mortgage is signed.