Why do we need front-end frameworks and what should be put into them and what should be into the back-end?

Question

Angular

I'm essentially a backend, with a medium version, javascript on the front - jquery.
But right now he went into freelancing, and there are angular and react everywhere.
And I just do not understand why they, what they give.
Well, let's say I understand them, but what to put on them, what to leave in the backend?
I used to take a view, put all the variables there, a little javascript and everything is cool.
And what about angular and others?
In fact, I have to give data there as in a view, like in another template engine?
And if I need to make modals and sliders, or something. Previously, I made a plug-in and it works. But now, is it all to write on these frameworks or also through jquery?

Answer 1

you have 2 virtual hosts, let's say on nginx
on one backend that gives data in json format
on the second frontend static ( html + js ) that pulls json from the
backend modals
and sliders are provided to you by the css framework (bootstrap, foundation, bulma, etc.), just substitute classes dynamically using js
to understand this course on angular 1 (not particularly relevant, but it will take only 3-4 hours):
https: //www.codeschool.com/pages/angular-1-vs-2
then from a root tracker of your choice:
Vue JS 2 - The Complete Guide (incl. Vuex)
or
Angular 2 - The Complete Guide
here's another free one for vue:
vuecasts.com