According to Genesis, Shem was the son of Noah in the genealogical line leading through Abraham.
Genesis 10 lists descendants associated with Noah’s three sons, and Genesis 11 traces a line from Shem through Arpachshad, Shelah, Eber, Peleg, Reu, Serug, Nahor, and Terah. Terah is the father of Abram, later called Abraham. This places Abraham’s Genesis genealogy within the line of Shem.
The genealogy is a textual ancestry list, not a modern genetic study or a complete population history. It also does not mean that every later people group can be mapped onto the sons with scientific precision. Later traditions expanded and reinterpreted these associations in different ways.
A common mix-up involves Canaan, who is listed as a son of Ham, not as one of Noah’s sons. Shem is also associated in later usage with the word “Semitic,” although modern linguistic classifications do not simply reproduce the genealogical scheme in Genesis.