2. c4
What is the Queen's gambit ?

It's considered one of the most solid openings due to its reasonable attempt to attack the center and develop with haste; in particular, it prevents the c-pawn from getting blocked by the queen's knight.

It is considered bad though, because after 3. cxd5 Nxd5 4. e4 you have a full center. If Qxd5 Nc3 wins a tempo
Hai, would appreciate an explanation. such a fancy name - but what does it actually mean?