Illustrated · 1 min
Vector Visualization
A vector can simply be seen as an arrow that has both a magnitude and a direction.
The "magnitude" of the arrow can be expressed as the length of the arrow. The direction is literally the direction that the arrow is pointing.
Quantities that have only a magnitude and no direction are called scalars.

Image source: by Anusha Rahman
This blue arrow is an example of a vector! It has a certain magnitude and is pointing in a certain direction.
We can use vectors when there is an object or person moving.
The closure property under scalar multiplication is essential for understanding why matrices form a vector space. The associative property of scalar multiplication is required for matrices to satisfy the axioms of a vector space.
Example
Say Robert is walking down the street from his apartment to the grocery store. The following image depicts his path:

Image source: by Anusha Rahman
The first blue star signifies Robert's apartment. The second blue star signifies the grocery store. The distance between the apartment and the grocery store is . The green arrow is the vector.
Let's think about how we know that the green arrow is the vector. It has both magnitude and direction! Its magnitude is , and the direction is to the right.
Applications of Vectors
We can use vectors for a lot of things! In the next couple of lessons, we'll learn about dot products, cross products, and other operations.


