What does radial symmetry mean? What is the type of symmetry found in chordates? Which are other phyla of the animal kingdom that present species with radial symmetry?

Radial symmetry means (biologically) that the animal structures are situated in a radial or circular pattern around a center point with nonexistence of sides, like right or left. An alternative type of symmetry in which structures are placed equally in the sides of a longitudinal axis is the lateral symmetry (the symmetry present in human beings, for example).