The voluntary advance of the e-pawn by 3 e5, although rather straightforward, is also in some ways the most principled continuation. By establishing an advanced post in enemy territory, White assures himself a space advantage and creates some preconditions for a future kingside attack. In the immediate future, however, White will have to concern himself with securing his position, since for the moment, his opponent obtains a relatively free hand, thanks to the release of the pawn tension in the centre. Both sides will continue developing, but Black also needs to achieve some more concrete benefits, since otherwise, at the end of the opening, a slightly inferior and rather prospectless middlegame will await him. As a rule, the next moves 3 … c5 4 c3 are played almost automatically,after which the various options come into play.
So here’s how grandmaster Akobian explains how to play Black side against advance variation.