There is a lot of questions here relative with bootstrap. I see a lot of people using it, so I tried to check, and I found the official bootstrap site, but there was only download section and a few words after that. Nothing that I can understand what is it for .. Just understood that it is frond-end helper. I have tried to find something by googling but nothing particular. Everything I found was computering bootstrapping, but not front-end one.
So my question is what is bootstrap at all, what it is used for, how it helps front-end developing and some more details explaining it.