Publisher, 3Blue1Brown, Video, YouTube
The first video of a series about linear algebra. Very good narration and animation. Suitable for introducing the vector concept to a high-school class. It covers up to and including addition of vectors and scalar multiplication of vectors. Importantly, it explains that there are different ways to think of vectors (coordinate, geometric, pure mathematical) and that they are all as good as each other.
16 February 2020 Edit: 16 February 2020
User submitted, thanks to Gavin