With an Digital Audio Interface,you input and output sound, into and out of the computer.
Most computer motherboards have a microphone and speaker jack built into them. Red is for input or microphone. Green is for output or speaker/headphones. They are very low quality. So only use them if can't afford to buy a dedicated soundcard.
Soundcards have what is called an AD/DA converter built into them. They convert Analog to Digital, to get the sound into the computer, And, They convert Digital to Analog, to get the sound from the computer to the monitor.
The time it takes the AD/DA converter to get the sound from the device to the computer, and then back to the monitor, is called latency. The shorter the time the better. The best soundcard will have a short latency time.
Sound cards are available with three types of connection method:
They are inserted into one of the PCI slots inside the computer.You will need to install the soundcard drivers with this type.
The external soundcard plugs into a firewire port in the computer.
They connect to a USB port in the computer.
Which is best soundcard? The one with: