Despicable Me's Vector.
A quantity that has both Magnitude (size) and Direction.
Developed to calculate complex forces in bridges and electricity.
Head to Tail method for adding. Tail is start, Head is the arrow.
In Plain English: A number just tells you 'how much' (Scalar). A vector tells you 'how much' AND 'which way'. Speed is a scalar (50mph). Velocity is a vector (50mph North).
In The Real World: Pilots. A plane flies forward at 500mph, but the wind blows sideways at 50mph. The pilot uses vectors to calculate the actual path.
Adding magnitudes directly. If you walk 3m East and 4m North, you didn't walk 7m total displacement. You walked 5m (hypotenuse).