Measures the alignment of its operand vectors on a scale of 0 to 1 u⋅v=uTv u⋅v=v⋅u (u+v)⋅w=u⋅w+v⋅w (cu)⋅v=c(u⋅w) ∣∣cv∣∣=∣c∣ ∣∣v∣∣ u⋅u≥0 u⋅u=∣∣u∣∣2 a⋅b=∣a∣∣b∣ cosθ