1) Data management 
A database schema (ə {respell|SKEE|mə}) of a database system is its structure described in a formal language supported by the database management system (DBMS) and refers to the organization of data as a blueprint of how a database is constructed (divided into database tables in case of Relational Databases). The formal definition of database sc...
Table relationships in a database, details ...
(In topic `Data Warehousing & BI`) the logical and physical definition of a database structure