An audio interface is a device that connects musical instruments, microphones, and other audio equipment to a computer. It converts analog signals into digital data, allowing for high-quality recording and playback. This is essential for musicians, podcasters, and sound engineers who need to capture sound accurately. Most audio interfaces feature multiple inputs and outputs, enabling users to record several audio sources simultaneously. They often include built-in preamps to enhance microphone signals and may offer MIDI connectivity for electronic instruments. Popular brands include Focusrite, PreSonus, and M-Audio, each providing various models to suit different needs and budgets.