First off, the H1 is the name of our block. There are different types of blocks that are commonly used which will be discussed as we use them. Everything after the block identifier is the template information, with the double percent signs around variable names. You'll see that where there used to be an ugly mess of HTML is now the clean BML blocks. The most common use of a full block is to make your PAGE definition.
Most people use a PAGE block to avoid doing the structure of their whole page.
If you think about it, the only two really necessary variables that change between pages and should be a part of the PAGE block are the title and the body. Again, my referring to BODY as a BML block variable has nothing to do with an HTML BODY tag. Actually, we're going to hide the whole HTML BODY inside our block definition. Let's also include the large centered text into our BODY block, since it's always going to be the same, just with the page's title inserted, which we're already going to pass. Well, yes, it kinda does.