This document provides an overview of freediving, including the different types of freediving disciplines for both open water and pools. It discusses key freediving equipment like masks, snorkels, fins, and their features. Breathing techniques that relax the body for longer breath holds are covered. Equalizing the ears and mask during dives is explained. The mammalian dive reflex and techniques like duck diving and finning are outlined. Hand signals and relaxation methods to improve breath hold times are also summarized.