Wikipedia as a collection of information is amazing, but its real strength is as a collection of findable information. Searching is useful for finding articles on specific topics, but you may need to search using a variety of names to find the article you're looking for. You can configure Wikipedia's search to search multiple namespaces along with other options; you can also use external search engines. Access the search engine on the left-hand sidebar, which also includes a number of other links and tools. Some of these links and tools are consistent throughout the site, whereas others change depending on the page.
Wikipedia also has intricate and well-developed structures for browsing, including links within articles, editor-constructed portals, the main page, and categories. These structures all use hypertext, where one page leads to another via links, with information split between various pages that reference each other. Categories, which show up as links at the bottom of pages that are categorized, provide a powerful way to browse through related pages, including pages categorized by quality (such as featured articles). Categories set up a classification system, with more specific areas becoming subcategories of broader areas.
In the next chapter, we'll home in on the individual articles, describing their specific parts. We'll cover what you can expect to find, as well as how to evaluate the quality of a given article.