Definition: A search engine at its most basic can be compared to a library card catalog arrangement – you think of a topic, and then you are able to pull up information based on the topic that you are looking for based on an underlying structural system that has organized information according to strict subject guidelines. And since the card catalog, i.e., search engine, is organized in a categorical/hierarchical fashion, you are (usually) able to retrieve relevant information in a timely manner.
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