This document provides an introduction to phonetics, the study of human speech sounds. It defines phonetics and explains its three branches: articulatory phonetics examines sound production, acoustic phonetics sound transmission, and auditory phonetics sound reception. The document outlines the importance of phonetics in accurately describing and differentiating sounds. It identifies the major speech organs and explains their role in pulmonic egressive airstream mechanism, the process by which air from the lungs is used to produce speech sounds. Finally, it introduces the International Phonetic Alphabet used to represent all English speech sounds.