This document discusses various methods of cooking food. It begins by explaining what heat is and how it affects different components of food like carbohydrates, proteins, fats, etc. It then describes different methods of heat transfer including conduction, convection and radiation. The major methods of cooking are classified as moist heat or dry heat methods. Moist heat methods discussed include boiling, poaching, steaming, stewing and braising where heat is transferred via water or liquids. Boiling and poaching are explained in detail with their purposes, effects and principles.