Question on MOSFET modes of operation

[Helena Wells]

TL;DR

I just came across some videos on youtube which aren't correct or so I think

I have studied the modes of the MOSFETs from this site https://www.electronics-tutorials.ws/transistor/tran_6.html however in many videos such as this : they don't agree with each other.Which is correct and which isnt?

 

[Baluncore]

There are many videos on the internet that get wrong.
Videos are usually a waste of time.

Refer to wikipedia for introductory information.

Understanding an electronic component, so you can use it in a design, does not require you understand the process used in it's manufacture.