An audio codec is a technology that compresses and decompresses digital audio files. It allows for efficient storage and transmission of sound by reducing the file size while maintaining quality. Common audio codecs include MP3, AAC, and WAV, each with its own strengths and weaknesses in terms of sound quality and file size. Audio codecs are essential for various applications, such as streaming music, video calls, and digital broadcasting. They enable devices like smartphones, computers, and speakers to play audio files smoothly. Understanding audio codecs helps users choose the best format for their needs, balancing quality and storage efficiency.