Recommended · for beginners
Logic Gates from Transistors: Transistors and Boolean Logic
Why people recommend it
Recommended to people new to digital logic as a way to see what the different logic gates do.
Watch for: Best before any formal digital logic course
In their words
A complete explanation would be long however, you can learn from some useful videos like [video] Let us know if you still have some confusion.
JaySabir on electronics.stackexchange.com, Aug 2020. CC BY-SA.