How to make a non-scalable image for a website?

Question

css

Dear web developers
I have a question, I have been in web development for a long time.
Could you tell me how to compose a picture, for example, on such sites
www.glowheadphones.com/#intro (video at the top of the page)
andrewgavrilov.me (video at the top of the page)
So that when the page is scaled, it does not change its size, and when this was exactly 1 screen

Answer 1

There are vh and vw units that set the size relative to the visible part of the screen (height and width respectively, 100vh is the height of the screen)

Answer 2

< img src="images/image.jpg" width="300" height="214" border="0">
This is how you can set the image size.