What is tracking in Photoshop and how to specify it in html?

Question

css

Good afternoon!
Please tell me how to specify tracking from Photoshop in css ..? The designer submitted the layout for layout and indicated the tracking at 140... What kind of animal is this? Or rather, not so - what is it, I sort of understand, but who is it in CSS ..?
Tracking is a method of increasing or decreasing the density of a text block
. Interestingly, I can specify in CSS - increasing the density of a text block
. Another kerning I can understand is letter-spacing. But tracking ... I
'm breaking my head ... Please tell me.

Answer 1

letter-spacing ≈ tracking.
140 photoshop tracking isletter-spacing: .14em

Answer 2

This is what he is.
Tracking * font-size / 1000 = letter-spacing in pixels.

Answer 3

Unlike kerning, which regulates the spacing between characters in certain pairs ("AV", "TA", etc.), tracking is applied to a group of characters (word, line, paragraph, etc.).
Here's a hemorrhoid ...)
I have both kerning and tracking in my layout ...
Thank you very much!