Sabaki is a generic name for some techniques required for high-level light play - but doesn't mean light play (as often asserted).
The concept of playing lightly is usually talked about in terms of defence. It also matters when you are attacking, though: because the attacker should be flexible and (in general) avoid over-commitment, as well. See for example the two different kinds of example cited at screening kikashi.
Tamsin Just a quick thought here: I was studying a game of O Rissei's in which he played in his opponent's sphere of influence, surprisingly close to his thickness. O made several moves, but not a single solid connection. It's not very profitable to capture a single stone in gote, but neither is it easy to attack numerous stones that are only loosely connected.