As you can see, each color-coded section of the funnel pictured above corresponds to a stage in the buying process. The widest tier at the top of the funnel represents “awareness,” the point at which potential customers are beginning their information search. The second tier is “interest,” roughly corresponding to the evaluation of alternatives described in the purchase process above. And, finally, the third and fourth tiers, “desire” and “action,” are self-explanatory.
As a software engineer myself, I can tell you that building funnels from an application standpoint takes massive amounts of work. There's a great deal of coding and integration that's required here. From email systems to landing page implementations to credit card processing APIs, and everything in between, so many platforms need to "talk," that it takes the bar too high for the average marketer.
One of the core concepts in the digital marketing industry is the sales funnel. While odd sounding at first, this single core concept can take a business from virtually non-existent and unknown to multi-million-dollar marketing machine with mass saturation, seemingly overnight. In fact, there are skilled practitioners who have built a career around implementing this single concept in business.