Why does bootstrap have such a screen resolution?

Question

css

Probably a stupid question, I'm wondering why in bootstrape (and in general), for container
media only screen and (min-width: 1200px) the container itself is width 1170 + padding 15 on the sides, this is understandable, then for (min-width: 992px) width 970px,(min-width: 768px) and for him 750px why doesn't it grow? Is there any explanation or is it just the standard, and also why do they padding 15 from the side?
I have wonderful thoughts, so don't criticize too much :)

Answer 1

Paddings are there just to keep the content from sticking to the edges of the screen.
It's awkward to just read, and a little padding improves viewing.
This is especially acute on mobile phones and sites in 100% width.
Why exactly 15 pixels, you have to ask Bootstrap.
For example, I always make the container 95%, and limit it to 1200 pixels.
That is, I do not have a clear padding, the smaller the screen, the smaller the padding.