This was the miraculous food God provided the Israelites after they left Egypt. Since they were crossing a desert area, God was doing them a kindness.
Exodus 16:31 describes it like white coriander seed and tasting like wafers made with honey. Later generations looked back and saw the forty years of manna as part of the great miracle of deliverance from Egypt and moving on to Canaan (Ps. 78:24).
Manna was literally “bread from heaven.” In John 6, Jesus refers to Himself as, figuratively, “the bread which came down from heaven . . . Your fathers ate the manna in the wilderness, and are dead . . . He who eats this bread will live forever” (vv. 41, 49, 58).