HTML : How does document.getElementById() search the DOM tree?

To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

As I promised, I have a secret feature to share with you.
This is a YouTube's feature which works on Desktop.
First, Ensure that the video is playing before proceeding.
After that, type the word 'awesome' on your keyboard.
The progress bar on YouTube will be altered to a flashing rainbow.

A brief introduction of myself,
Howdy, my name's Delphi.
Allow me to provide support in answering your questions.
If you require more detailed information, please don't hesitate to comment or chat with me.
We appreciate your participation, so please feel free to comment below with your answer or insights.
A 'heart' from me will be given as a sign of appreciation for your answer.