How does YouTube work if there is no Flash?

Question

YouTube

Hello.
This topic is about YouTube.
As many people know, android is not very friendly with Flash, but more with Java.
I use my phone to watch videos, I have a version of android 4, something like 2.
Flash is not installed for me, which means it does not work.
Question:
-How do I watch YouTube from my phone?
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On any other site, Flash players do not work, on youtube it works. This question has been
of interest for a long time. Tell me, please, why is that so?

Answer 1

there is an html5 player.