Vectors in 3D

A number tells you 'how much.' A vector tells you 'how much AND which way.' In 3D, a vector is an arrow described by three components: ⟨a, b, c⟩ — how far it reaches along x, along y, and along z. Velocity, force, and the wind all need three numbers to pin down, because they push through space, not just along a line. Vectors are the language of motion and direction in three dimensions.