It's a foundation to other stitches you will learn in additional videos. Remember in school, you'd be learning math and your teacher would say, "This is a basic idea that you'll build on."? Well, totally the same in crocheting (and just about anything you do in life!). You can do just about anything with the single crochet, too. The single crochet is a small, compact stitch that can let allow you to crochet in straight lines, diagonals, circles, and many other shapes. As long as you know the single crochet, you can apply it to other techniques.
I like it because it's simple, and like I said -- compact. In addition, I think it makes a beautiful design and texture. Well, with that here's the video!