The idea goes back to the AIDA Model of the late 1890s: attention, interest, desire, action. Modern versions usually speak of the top, middle and bottom of the funnel. Content at the top reaches new people, the middle builds trust and helps people compare, and the bottom makes it easy to act, with offers, proof and a clear call to action.
The funnel is a simplification. Real people skip stages, go back and forth and decide through conversations no dashboard sees, which is why the customer journey gives the fuller picture. Its practical value lies in diagnosis: comparing the numbers at each stage shows whether the problem is too few people coming in or too many dropping out along the way.
