Audio refers to sound that is captured, transmitted, or reproduced. It can include music, speech, and other sounds that we hear in our environment. Audio is typically measured in terms of frequency (pitch) and amplitude (volume), which determine how we perceive different sounds. In modern technology, audio is often recorded and played back using various devices, such as microphones, speakers, and headphones. Digital audio formats, like MP3 and WAV, allow for easy storage and sharing of sound files. Audio plays a crucial role in entertainment, communication, and education.