Think of a search engine as a computerized card catalog, where each card represents a web page. You type in your search criteria, and the engine returns a list of web pages that match your request. Usually the list will be broken into groups of ten entries, but there may be hundreds of pages on the list. Not all of them will be what you had in mind, but chances are, something useful will be there. The web has proved to be an excellent resource for government agencies which have lots of data.
Agencies can quickly and cost-effectively distribute that data to a wide audience.
This information is published on the World Wide Web where it can be accessed free of charge by anyone with a net connection. Other agencies provide their data in the same manner. Researchers can access this original source material at any time. Anyone can publish a web page, which means that people who have specialized knowledge can easily share it with others. Such knowledge is often the subject of personal home pages.