Reproducing Kernel Hilbert Space explained

Couple of simple yet in-depth resources to learn about Reproducing Kernel Hilbert Spaces (RKHS).

I am trying to learn application of Gaussian process to Contextual Bandit problem in re-reinforcement learning. Needed a refresher on the RKHS and found this write up: From Zero to Reproducing Kernel Hilbert Spaces in Twelve Pages or Less and RKHS Lecture on YouTube useful.