Answer the question first. Massive open online course network focuses on IT programming industry, and it has been tested for about 6 years now. It was recorded by Bat Daniel and then audited by professionals. Quality, quantity, update speed of new technology and so on are guaranteed.

"It doesn't matter if you meet the same answer again, the same answer." "reiterate: massive open online course networks are actually divided into two categories: free and paid. The massive open online course network started from free, and so far more than 80% are free. " The reply is for "enthusiastic netizens"