There are a lot of questions here related to Bootstrap. I see a lot of people using it. So I tried to research it, and I found the official Bootstrap site, but there was only a download section and a few words after that. Nothing that explains what is it for... Just understood that it is a front-end helper. I have tried to find something by Googling but found nothing specific. Everything I found related to the computer science definition.
So my question is: what is Bootstrap at all, what is it used for, and how does it help front-end development? I would also like some more details explaining it.
The official boostrap website is updated and includes a clear definition.
"Bootstrap is the most popular HTML, CSS, and JS framework for developing responsive, mobile first projects on the web."