Final answer:
An Internet catalog with broad categories that subdivide into smaller ones is called a directory, which organizes web content systematically.
Step-by-step explanation:
An Internet catalog that starts off with broad categories, which are then subdivided into smaller categories, is known as a directory. These directories are structured to provide a means of classifying and organizing web content into a hierarchy of categories. Unlike a search engine, directories do not rank information by authority or relevance but provide a systematic way to navigate through different topics, starting from a larger subject to gradually more specific ones.