1 [computing] The structure or design of a database or database object, such as a table, view, index, stored procedure, or trigger. In a relational database, the schema defines the tables, the fields in each table, the relationships between fields and tables, and the grouping of objects within the database. Schemas are generally documented in a data dictionary. A database schema provides a logical classification of database objects.
2 [computing] A set of rules, stored in a file, that describe the structure of an XML document. The number, type, and order of elements allowed in an XML document are described in the schema. An XML parser can compare XML documents against the schema. An XML document that uses open and close tags properly is said to be well formed; if it also follows the rules of its designated schema, it is said to be valid.