Most prospects will look to enter this stage after identifying your offering as a possible solution and completing the information search process described in the earlier stage. However, some customers might be introduced to your brand after completing Stage 2 with your competitors, as in the case of an industry blog running a comparison chart of the different competitors in your space.
If you're wondering what a sales funnel is, simply imagine a real-world funnel. At the top of that funnel, some substance is poured in, which filters down towards one finite destination. In sales, something similar occurs. At the top, lots of visitors arrive who may enter your funnel. However, unlike the real-world funnel, not all who enter the sales funnel will reemerge out from the other end.