What are the services of questions and answers on the topic of IT and business?

Question

Communities

Very often you have to look for answers to some questions about IT or business in Google, which takes a lot of time. It would be nice to have links to some question-answer services, like Toaster or Mail.ru answers, but not on a general topic.
I once saw a very large service of questions and answers in the bourgeoisie, but I don’t remember the link to it, can you tell me?

Answer 1

Quora .

Answer 2

stackoverflow
https://www.stackoverflow.com/