The span element on the left here has been floated to the left. See the source!
The span element on the right here has been floated to the right. See the source!
The text in this paragraph has been aligned to the left
The text in this paragraph has been aligned to the center
The text in this paragraph has been aligned to the right
The text in this paragraph has been justified. Width justified text you don't really see any difference in the way that it looks until there is more than two lines of text, so I've waffled on a little here to show that point!