Casing hangers as the name implies is used to hang the casing in the wellhead. Some locations may elect to set casing on the bottom of the hole but the most common
Casing Hanger - an overview | ScienceDirect Topics
Sentry Wellhead Systems
Casing Hangers
Slip Type & Wellhead Casing Hangers - Casing Slip Hanger | G.B. Industry Co.