Inducing move
In a sequence , , , you can call an inducing move if is the key point, but the exchange / makes it look even better.
This type is quite common. Black wants to connect at the point . After this looks forced, but works well now in two directions.
dtch1997? This is an example taken from amateur low-dan play. Black has approached White's enclosure, intending to make territory on the upper side. White has resisted with 2.
Pushing out directly with 1,3,5 doesn't help Black. White make a light, resilient shape in the center of the board with 2-6. Black might try to fight with the pincer of 7, but White presses at 8 and now has no need to worry about the center group. Furthermore, Black's group on the top side is not completely settled. If Black plays away now, White blocking at 'a' will separate Black's two groups on the top side; if Black b, the sequence to e keeps White's position intact and leaves Black overconcentrated. In any case White has succeeded.
Instead, Black first plays the inducing move of 1. White's strongest response is to bump with 2, but then Black plays 3 naturally, splitting White's shape. Now the follow-up with 'a' would make very nice shape for Black, so White feels obligated to follow-up with 4.
kmr - actually white 2 does not make much sense, its just force black to play where he want to play anyway. White should just patiently fall back ( b or c ). Playing 2 is inconsistent with shoulder hit.
White 4 is big mistake (white should play "a" instead. After white 4, black can play "a" himself and white is in big troubles since he either lose stone at "4", or black will live in corner. White can get some outside influence, but black will get both profit (he will take corner which was white territory before) and sente, a good trade for him.
At the end of this sequence, Black has managed to fill an extra liberty on White's attacking stone compared to Diagram 2. Now, it will be hard for White to attack Black's group effectively, and Black will probably surround the top with little difficulty. Concretely, 'a' and 'b' are miai for Black. In exchange, Black has slightly enlarged White's corner, but that corner started off as White's anyway, so this is not a big loss. Overall, Black has profited from this exchange.
Dieter: this elaborate example must come from somewhere but I agree with kmr that it's a festival of bizarre moves. I checked with KataGo and it confirms: none of the moves displayed is the blue move and White's hane is an outright mistake.