One of the analogies for the opening moves of a Go game is creating military bases throughout the world or a country. These bases do not equal territory under control, but they result in influence over a given region which, after a properly executed campaign, may become a territory.
This is one of the most interesting aspects of a Go game: to balance the potential with the actual, a struggle that also exists, lehavdil, in Judaism, both in Halacha (e.g., Beis Hillel vs. Beis Shammai) and Chassidus.
To play a stone in an empty region of the board to create influence over it before your opponent does or to play a conservative move that strengthens an already placed stone (or an already existing group) bringing existing influence closer to becoming a control over a territory? Such questions are asked throughout the opening of a Go game.
(Of course, these are just very basic concepts that are applied for more abstract calculations. Oftentimes, an attack on an enemy's base results in a sequence of moves, after which the enemy, defending his area of influence, has built a secure territory, and you have built a wall facing the center that now has a great deal of influence.)
The above introduction was to explain the following figure. In it, most of the stones played in the fuseki (the opening) of a game between two strong amateurs are marked with triangles (some stones are not there because they were captured in the mid- or endgame). The figure itself shows the end of the game. It is interesting to see which territories resulted from which opening moves...
(source: Invitation to Go by John Fairbairn)