Strongly recommended
Capacitors and Capacitance: Capacitor physics and circuit operation
Why people recommend it
Animated explanation of what happens inside a capacitor, widely praised for building intuition about charge and current flow.
Watch for: Narration style divides opinion
In their words
You can watch this great and short video, that will give you more intuition than I could ever give by just writing.
MPA95 on electronics.stackexchange.com, Sept 2020. CC BY-SA.