What is the purpose of static site generators?

I keep hearing about static site generators in React, Vue or Jekyll etc. I'm confused as to what purpose they serve? Can't I use vanilla js, CSS, and HTML and have a static website? How's static site generator useful?

How is the state of the applications maintained efficiently using jQuery or similar libraries? See the description for more details!

I started my career as an Angular Developer and moved on to use React JS. I'm just curious as to how is the state of the application maintained efficiently using jQuery or similar libraries. I've had to code a certain dashboard component in jQuery in...

How to change fonts in Sublime Text? Also, suggest other possible customisations.