Hmmm, Emmet. You will either love it, hate it, or just... never use it. Why? Well, it allows you to easily generate nice long lists with a few simple short cuts, or create full tables if you're so inclined. But whilst it's cool to know, the fact is, many of us will use For loops (or similar) to output lists, rather than generating static html.
But if you like it and want to know more, check out emmet.io