A Salesforce Lead refers to any company or individual that’s considering joining your organization as a customer but hasn’t yet entered the sales discussion. A Contact in Salesforce is a company or individual that has completed a sales discussion, qualified for sales opportunities, and been converted from a Lead to Contact.
This difference in category indicates how a customer should be treated within Salesforce. Leads should receive marketing, but only qualified Leads should get aggressive marketing as they’re guided through the sales process. Contacts will no longer receive aggressive marketing, but they should receive a high level of attention for all of their support needs.