This is a simple, but effective, method for organizing your views and making them instantly understandable for a wide range of users. Let's look at an example of how not to do this in an imagined "Calendar" app user interface:

Simply by altering the type size by a noticeable factor, we can show the user the most relevant information first:

Scale up the information that you want users to see first, or that you think they'll find most useful, and they can read on further for extra detail. This is the reason for a lot of news and factual journalism settling on this format: