Selection and absorption
Absorption is a model knowing your brand from training data; selection is a retrieval system picking your page as a source for one specific answer. They are different phenomena with different causes and different fixes.
What we can add
This is our distinction and almost nobody separates the two, which is why so much AI-visibility advice contradicts itself. Absorption responds to being talked about over years; selection responds to a single page being the most checkable answer to one question today. Advice that conflates them tells you to do brand marketing to fix a retrieval problem.
Go deeper