The term schema basically means description. In simple words, the database schema is the description of the database. However, in the database world, the database schema is defined as the logical representation of the entire database. The database schema is defined by the logical data model which consists of database entities represented by the database tables and the relationship between the tables. The database schema types also include logical schema , physical schema and the view schema. However, the logical and physical schema are the most common terms used in the context of database design. A database schema represents the logical configuration of either entire or part of the  relational database. The database schema also means both visual representation and as well as database integrity constrains defined by a set of formulas. These formulas are expressed in a data definition language DDL, such as SQL. The SQL stands for structured query language. A database schema indicates how various database entities relate to one another, including tables, views, stored procedures, and other database design features.