If you would like to learn more about K-Nearest Neighbours algorithm for classification, this interactive demo will help you understand the parameters that go into it, including the N value we experimented with in the previous video: http://vision.stanford.edu/teaching/cs231n-demos/knn/
To learn more about how this algorithm works, you can also check out this article: https://www.analyticsvidhya.com/blog/2018/08/k-nearest-neighbor-introduction-regression-python/