Learning Start: Bootstrap 3 or 4?

Question

css

To be honest, I thought I could do without the advanced skills of this framework (in general, I have some experience with it), but I look at freelancing this is a popular thing.
Accordingly, the question arose - if you sit down to study it in depth, is it possible to immediately start working on Bootstrap 4? Does it completely replace Bootstrap 3? Are there clear customer requirements to use the 3rd version?

Answer 1

Learn 4 at once. Everything is detailed in the official help:
v4-alpha.getbootstrap.com/getting-started/introduction
To understand how it works in principle, you can watch this overview:
https://www.youtube.com/watch?v=qIIvIBc7-_M&list =P...

Answer 2

If I were you, I would strive to learn how to typeset without bootstrapa in principle ... Learn flexbox and you will be happy