Database state Database state is the actual data stored in database at particular moment of time. Internal schema:- • Describes physical storage structure • Access paths(indexes) • Use physical data model • Show low leveldetails Conceptual schema:- • Describes database schema at conceptual level • Uses conceptual model • Hides low level details • Describes database schema for a group of users External schema • Describes database schema at conceptual level • Uses conceptual data model • Describes database the part of database schema in which a group of users interested. Data independece DDL data definition language Data definition is used to define database schema. Data manuplation language Data manuplation language store database schema in database management system catalog. SDL VDL Query language Query language is used to insert,modify and extract data of database management system. Host langauge Database utility Thes are a set of tools to allow fast and easy data transfer, maintenance, and database administration of databases. Catalog A file that contains the record of table in DBMS and their names etc. Client/Server architecture In client server architecture one system act as server and the other ones as client the client requests the server and the server provides services to their clients.