These records not only provide an excellent genealogical tool for research, they also provide lawyers with the tools to conduct title searches to property that is being bought or sold by their clients.
Attorneys usually hire title searchers to trace the property backwards from the present.
Deed indexes are grouped together by year of sale. You may find a book that covers all deeds recorded from 1975 through 1980. It will lead you to a book of deeds where you will find a copy of the deed. After reading the deed, you can determine when the seller bought the property and from whom. This date and these names will lead you to the next index.