This document discusses different types of surgical retractors. It begins by defining a retractor as an instrument used to separate surgical incision edges or hold back underlying tissues. There are two main categories: hand-held retractors which must be held during surgery, and self-retaining retractors which have mechanisms like screws or clamps to hold tissues without assistance. Several examples of specific retractors are described, including the Balfour abdominal retractor, Finochietto rib retractor, and Gelpi self-retaining retractor. Common hand-held retractors like the Senn, Army-Navy, Langenbeck, and Morris are also outlined. All described retractors are sterilized using autoclave methods