An audio interface lets you get audio signals in and out of your computer. There are so many ways of doing it, and it depends on how you like to work and what you're trying to do. There’s basic interface that’s a box converting analog audio to digital audio that the recording software in your computer can understand, and convert it back to analog audio when you want to hear it. There are better quality converters and they have what's called "jitter correction" to compensate for small timing variations. Buy audio interfaces online at best price at Delhi Sound Store.