Speed: Bullet to Correspondence Rating:
With 1. ... e6 black wants to support the pawn push to d5 next move. Wanting to establish d5 as a secure and stable anchor in the center.
However, the French Defense does come with two major concerns for the Black player. First, the Bishop on c8 may end up as a "French Bishop", finding itself trapped behind blacks own pawn chain; f7, e6, d5. Thus not contributing it's full power to the battle. Secondly, white can neutralize most of the long term plans for black's opening by entering the Exchange variation. There White responds to d5, by playing exd5. With a symmetric position on the board, the game may continue into a unceremoniously draw, with neither player being properly challenged.
Despite that, French does have considerable appeal. With either c5 or f6 it's possible for black to put increasingly more pressure on White's center. Thus, the opening is well worth study, the fight for the center will bring plenty of instructive moments. From White's perspective, it may also be tempting to move the e4 pawn, to e5. By having the white pawn on e5, Black's knight is prevented from occupying f6. Consequently, there may be good opportunities to attack the Black kingside.