This is just some paragraph text. Much of a document is paragraph text with no styling.
The advantage of using Markdown is that the formatting isn't part of the text you are editing.
The result is that you can focus more on the words you are writing (and the changes made to them) and less on changes to formatting.
LifeHacker has a good article on the advantages. You can also see this text over at Hashify to see a slightly more advanced editting interface.
Well, you can do very simple dot points:
- like this one,
- and another,
- which can be nested as well,
- without too much trouble.
You can also do simple numbering, which will work out what you mean:
- Notice that the numbering,
- doesn't have to be in order,
- which is handy if you shift your points around,
- (as people occasionally do from time to time).
You can add emphasis and strong highlights to text. Note that these use the <em> and <strong> tags in HTML, which means that how they look can be determined by web designers/developers later. (By default they look like italics and bold).
Quotes blocks look a lot like old style email quotes. Again, because they tell the document it is a quote, not how to show it, they can be styled later.
You can also add images very easily (eg. for charts):