The document discusses various metrics and estimation techniques used in project management, including burn down charts, velocity, and planning poker. It describes burn down charts as a way to track work completed and remaining over time. Velocity measures the amount of work a team can complete within a sprint. Estimates are not fixed but are meant to be quasi-estimates and continually re-evaluated. Planning poker involves the team anonymously estimating tasks in pairs to reach consensus and avoid influence from others like managers.