In marketing, the terms "prospect" and "lead" are often used interchangeably, but there is a subtle difference between the two.

A prospect is a potential customer who has shown some level of interest in a company's product or service, but has not yet been qualified as a sales opportunity. In other words, a prospect is a potential customer who fits the target market and has expressed some form of interest or engagement, such as by filling out a form or subscribing to a newsletter.

A lead, on the other hand, is a prospect who has been qualified as a potential sales opportunity. This means that the lead has gone through some form of additional screening or qualification process, such as by answering specific questions about their needs or budget, or by demonstrating a higher level of engagement with the company's content or offerings.

In other words, all leads are prospects, but not all prospects are leads. Leads are typically considered to be more valuable than prospects, as they have been identified as having a higher likelihood of becoming a paying customer. As a result, businesses may focus more of their sales and marketing efforts on converting leads into customers.