Direct Answer
A lead is anyone who has expressed initial interest by submitting a form, calling, or downloading content. A prospect is a lead who has been qualified — meaning the team has confirmed they have budget, authority, need, and timeline (BANT). All prospects are leads; not all leads become prospects.
Voice answer (≤30 words)
“A lead has expressed initial interest. A prospect is a lead who has been qualified for budget, authority, need, and timeline.”
Track lead-to-prospect conversion as a sales-team KPI separate from prospect-to-customer.
Bad leads usually = bad targeting upstream. Fix the source before blaming the sales team.