Schema is a representation of a plan or theory in the form of a diagram, rules or model. The word schema (Both schemata and schemas are used as plural forms) is derived from the Greek word skhēma, which means a plan or figure.

Schema definition
Schema is an outline, protocol or a model used to represent a structure, semantics or a plan.

In computer science, the word “schema” may refer to:

  • Database schema
  • XML schema
  • Expression or inference rule in artificial intelligence(AI).
  • Genetic algorithms

Schema should not be confused with, a website which provides a collection of schemas, i.e., html tags, that webmasters can use to markup their pages in ways recognized by major search engines. Search engines including Bing, Google, Yahoo! and Yandex rely on this markup to improve the display of search results, making it easier for people to find the right web pages.