An absolute essential to a successful recording is getting things right at the source, and here, he focuses on doing it with an electric guitar. He also contrasts the sounds of a couple of very different electric guitars for illustrative purposes.
You can see the process as well as listen along to really hear the difference.
Joe Gilder is a Nashville-based engineer, musician, and producer who also provides training and advice at the Home Studio Corner. Note that Joe also offers highly effective training courses, including Understanding Compression and Understanding EQ.