The two terms, 'lead' and 'prospect' are often confused in the art of email lead generation. Both have some differences. In other words one is not the other. A lead is a contact that you gained through the procedure of capturing via a form embedded on to your landing page. In fact a lead is just a contact that has shown some interest in your product or service.
On the other hand, a prospect is the one who has shown more inclination towards knowing about your product or service and has answered your introductory email as well. That means this person is likely to become your customer shortly. Not only that, such persons superbly fit into your ICP or Ideal Customer Profile which means they are more likely to buy your products and services in the future.
A lead just comes into your contact just by signing up and they are not qualified to be drafted into your ICP whereas a prospect is a qualified person who, intent on buying your product or getting a demo after calling you much to your delight. A lead is often called as a marketing qualified lead whereas a prospect is often called as a sales qualified lead.