ELI5: Explain Like I'm 5

Cross product

The cross product is a way of multiplying two vectors together to find a new vector. A vector is like an arrow, it has length and a direction. When you multiply two vectors together with the cross product you get a new vector that is at a 90 degree angle from the first two vectors. The length of the new vector is equal to the length of the first two vectors multiplied together and then multiplied by the sine of the angle between them.