This document discusses different types of neck dissection procedures used to remove cervical lymph nodes. It describes the standard radical neck dissection, which removes lymph nodes from levels I through V, as well as the internal jugular vein and sternocleidomastoid muscle. Modified radical neck dissection spares one or more of these structures. Selective neck dissection removes lymph nodes from certain levels based on the primary cancer site, preserving other lymph node groups. Extended radical neck dissection removes additional lymph node groups or tissues beyond a standard radical neck dissection.