This document discusses different types of lighting sources used in photography including natural light from the sun and moon as well as artificial lights. It describes the effects lighting can have such as highlighting subjects, conveying mood, and creating shadows. Various lighting styles like high-key, low-key, hard light, and soft light are defined. Basic portrait lighting techniques involving key, fill, and back lights are also covered. The document emphasizes that mastering lighting is an important photography skill and encourages taking sample shots to test lighting setups.