In each case, we saw that there were a number of advantages and drawbacks to each approach. Again, each method will be shown to have unique advantages and disadvantages.
Length units Using length units is perhaps the most popular approach for setting font sizes.
The first five of these units are called absolute length units . They correspond to real-world units, which are assumed to have standard, unvarying lengths that always have the same relation to each other. The last three are a bit more fluid, and are therefore known as relative length units . The important differences between these types of units will emerge as we talk about how font size works. Let's say that we want to create text that is exactly 18 pixels in height.