Mark Henderson answered
There are two main ways to connect a guitar to your computer. The most basic way is to plug your guitar or amp straight into the microphone jack of the computer. The second way is to use a USB audio interface.
Connecting your guitar straight into a computer via the headphone jack will not yield the best results, but can be useful if you just wish to connect a guitar to your PC's speakers.
Connecting a guitar to a computer through a dedicated audio interface will greatly increase the sound quality and will make it possible for you to professionally record on your computer.
- Plug your guitar or amp straight into the microphone jack of the computer.
- If you wish to get good sound quality from your recordings plug your guitar in via a USB interface.
The microphone jack
Connecting your guitar through the microphone jack will be sufficient if you do not wish to record your playing. You may experience latency issues and poor sound quality using this method, however.
- Simple and cheap method of connecting your guitar to PC speakers.
- Not advisable if you wish to record your playing.
USB audio interface
A dedicated USB audio interface is needed to get the best sound quality and minimize latency. The audio interface will connect to the USB port of your computer and contains a powerful sound card. You may need to purchase a digital audio workstation (DAW) to maximize the capabilities of the interface.
- Allows you to connect more than one instrument at a time.
- Inexpensive method to achieve professional-sounding results.