"Link in Description" Where?

[Mike J G]

I view a video tutorial and the speaker says he has "put a link in the description" and sometimes the word "below" is included. I'm never able to find that link. Is anyone able to tell me exactly what that means and how to find it?
Sometimes I feel like a complete ignoramus as a result. Please help if you can.
Mike.

 

[voyagerfan99]

In a YouTube video, the description area is compressed. You need to click the "Show More" at the bottom of the description to see more.