Exodus 14 and 15 describe a wind driving back the water through a night, Israel crossing on dry ground, and the sea returning over the pursuing chariots. The Song of the Sea that follows is one of the oldest passages of Hebrew poetry in the Bible, and the episode became the founding image of deliverance for Judaism and for everything downstream of it.
The name is not straightforward. The Hebrew reads yam suph, which means sea of reeds or sea of papyrus, and the Septuagint rendered it in Greek as the Red Sea, which is how it entered Latin and every European Bible after. Since papyrus does not grow in salt water, many scholars have looked instead to the lake and marsh country of the eastern Nile delta, and Nahum Sarna's study sets out both the philology and the difficulty of fixing any route on the ground. Israel Finkelstein and Neil Asher Silberman go further, arguing from the archaeology of the Sinai that no large migration of the kind described has left a trace, and reading the narrative as a later composition; other scholars hold that a small event underlies it. Nothing in the debate has changed what the story does.
Its liturgical life is enormous. The crossing is recited every Passover in the Haggadah, is read by Paul as a figure of baptism, is sung in the Orthodox canon of the resurrection, and appears in the Quran in the account of Musa and Pharaoh, where the water closes over a king who claimed divinity for himself.