What are digital products?
Some products exist only on a computer, however they are still sold for real money. Examples of these include eBooks (which are just like normal books but instead of a hard copy they are just a file which you can download), training courses (on anything, from learning Spanish to learning about internet marketing), software and much much more.
The advantage of selling digital products is that you don't have to pay any manufacturing or distribution costs. Once you've made the product, everything you sell is virtually profit! This is why many people create their own digital products themselves, for example writing an eBook on a subject, and then selling it.