Shem was Noah’s son traditionally associated with the line leading to Abraham.
Genesis 10 and 11 trace a genealogy from Shem through several generations to Terah and then Abraham. For that reason, Jewish, Christian, and Islamic traditions commonly connect Shem with the ancestral line of Abraham, although the traditions differ in details and interpretation.
Noah’s other sons are Ham and Japheth. Genesis 10 presents all three as ancestors connected with different peoples, so identifying Shem with Abraham’s line does not mean the other sons are unimportant in the narrative.
The word “Semitic” was later formed from Shem’s name and became a linguistic and cultural term. Modern scholarship treats language families and identities with more complexity than a simple genealogical label, so the biblical genealogy and the later word should not be treated as identical categories.