You can categorize leads by their place in the sales funnel: top of the funnel, middle of the funnel, or bottom of the funnel.
The top of the funnel (TOFU) consists of cold leads in the awareness stage who have just started learning about your brand.
The middle of the funnel (MOFU) consists of leads in the consideration stage who have identified a problem they have that you help solve. They’ve started to research their options.
The bottom of the funnel (BOFU) consists of leads in the decision stage. They’re deciding which product to with and it’s up to you to convince them.