A View is a set of system instructions that will look for content containing criteria you define and then display that content according to how you set the output configuration options. A View creates a page to show output, but by itself is otherwise empty if no content meeting the defined criteria exists.
Let's look at a scenario. You've been working on your site for a month or two now, and you feel like you've mastered the basics—all the topics in the Training > For everyone and > For managers sections are familiar to you. Now, you find yourself looking critically at your site and thinking, "I feel like I should be able to do more with this."