Demand generation and lead generation are often used interchangeably in B2B marketing, but they represent fundamentally different approaches to building pipeline. Lead generation optimizes for lead volume and cost per lead. Demand generation optimizes for pipeline quality, account-level engagement, and revenue influence. The distinction matters because optimizing for the wrong metric drives the wrong behaviors - teams measured on MQL volume will sacrifice lead quality to hit their number, while teams measured on pipeline influenced will focus effort on the accounts that actually generate revenue. This guide explains both approaches, their key differences, and how mature B2B teams use them together.