What's the Difference Between a Search Engine and a Directory?
FAQ
#1:
Q:
What's
the difference between a "search engine" and
a "directory?"
A:
Both search engines and directories
are made up of databases or catalogues of websites. The
real difference between them is how those databases are
indexed. A search engine uses a robot or web crawler to
automatically find websites and index them based on an
algorithm (a program made up of a set of rules determining
that search engines ranking criteria). A directory, on
the other hand, is structured by topic-based categories
and ranking criteria pre-determined by humans. Getting
listed in a directory is a manual process.
Example: Google is a crawler-based
search engine. Yahoo! and DMOZ are search directories.
Note that many crawler-based search engines also extend
the option of for users to submit manual listings. Today’s “Hybrid
Search Engines” are likely to display both crawler
and human-powered listings, although they typically favor
one over the other.
See also Which Search Engines
Matter How Search Engines Work
