Answer: What is a search engine?
A Search Engine has 3 Basic Parts
1. Spider (crawler, link finder): a computer program that harvests web links from page to page
2. Index: a database that is organized and searchable of the Spider's harvested results
3. Search and retrieval mechanism: Software that allows users to search the Index and return results in a predetermined order.
But a Search Engine also is commonly used to refer to any software that searches an Index of Words or material types
Examples
A. "Small" page related Search Engine - To search this page for the word "Usenet" Click on EDIT in your browser menu, then Click (Find (on this page) . Enter your term and search.
B. Database or Index Specific - Searches only for content within an
enclosed site
Examples - Searching the www.smcvt.edu site,
Online Catalogs, Periodical Indexes like Lexis-Nexis
C. Directory Search Engines -- Searching for content or web pages
submitted by hand. In other words materials are found and maintained by a human
being.
Examples - AskJeeves, Google Directory
D. Large Search Engines - These search engines use the "3 Basic Parts" listed above. They try to find everything on the Internet and fail miserably for a number of reasons.