A site without its creator or responsible agency identified is like a book that has no author or publisher on it. You need to determine if you are looking at the official site of an agency or a bootleg site. You also should check for the credentials of the author or organization. Information on the Internet does indeed go out of date. Check to see there is a date of last revision on the page or on the site.
Organizations create services, products and advertising with their audience in mind.
This is also true of their web sites. An individual's personal home page may or may not be oriented to an identifiable audience. Many web sites have one or both of these tools to help you understand what is on the site. With a site map and a search engine, you can see just what they offer and how to find your way around. A site map is a visual representation of the areas or categories or pages within a site.