A lead is a person who has expressed interest in the product or service that a company offers.
Collecting a lead means that you have already skipped the first two steps of the sales cycles which are the dreaded prospecting and cold-calling and can directly proceed to a warm call.
A warm call is much more valuable than a cold one.
Many have already declared cold calling dead and would rather focus on warm leads because when you contact a warm lead, a person is expecting to hear from you or at least has shown some interest towards your business.