ELI5: Explain Like I'm 5

Vector measure

Vector measure is a way to measure the size or length of a vector. A vector is a line that has a start and end point, and can go in any direction. To measure the size of the vector you need to know how far the start point is from the end point. To figure this out, you use a ruler and measure the distance between the start and end point of the vector. Then you have the size or length of the vector!