Define the various terms of Database.

 a) Data Dictionary: 

A data dictionary is a centralized repository that stores metadata and information about the data stored in a database. It contains detailed descriptions of data elements, their attributes, relationships, data types, and constraints. The data dictionary serves as a reference for database administrators, developers, and users to understand the structure and meaning of the data in the database.

b) Primary Key: 

A primary key is a unique identifier for each record in a database table. It uniquely identifies each row in the table and ensures that no two rows have the same key value. The primary key constraint enforces the uniqueness and integrity of data in the table, and it is used as a reference point for establishing relationships between tables.

c) Relationship: 

In the context of databases, a relationship refers to the association between tables based on common attributes or keys. Relationships define how data in one table is related to data in another table. The most common types of relationships are one-to-one, one-to-many, and many-to-many. Relationships are established using foreign keys, which link the primary key of one table to a corresponding column in another table.

d) DML (Data Manipulation Language): 

DML is a subset of SQL (Structured Query Language) used to manipulate and manage data in a database. DML commands include INSERT (to add new records), UPDATE (to modify existing records), DELETE (to remove records), and SELECT (to retrieve data). DML allows users to interact with the data stored in the database and perform various data manipulation operations.

e) SQL (Structured Query Language):

 SQL is a standardized programming language used for managing and manipulating relational databases. It provides a set of commands and syntax for defining database structures, querying data, and performing various database operations such as insertion, deletion, updating, and retrieval of data. SQL is widely used by database administrators, developers, and users to interact with relational databases.

f) Data Integrity: 

Data integrity refers to the accuracy, consistency, and reliability of data stored in a database. It ensures that the data in the database is correct and valid, and it meets the specified constraints and business rules. Data integrity is maintained through the enforcement of integrity constraints such as primary key constraints, foreign key constraints, uniqueness constraints, and check constraints.

g) DDL (Data Definition Language):

 DDL is a subset of SQL used to define and manage the structure of database objects such as tables, views, indexes, and constraints. DDL commands include CREATE (to create new objects), ALTER (to modify existing objects), and DROP (to delete objects). DDL is used by database administrators and developers to design, create, and modify the database schema.

h) Data Security: 

Data security refers to the protection of data from unauthorized access, disclosure, alteration, or destruction. It involves implementing security measures and controls to safeguard sensitive data stored in a database from security threats and breaches. Data security measures may include access controls, encryption, authentication, authorization, auditing, and data masking to ensure the confidentiality, integrity, and availability of data.

i) Database System: 

A database system is a software application or platform used to manage and store structured data in a computerized environment. It consists of a database management system (DBMS) that provides tools and utilities for creating, organizing, retrieving, and managing data in a database. A database system includes various components such as database engine, data storage, query processor, transaction manager, and user interface. It serves as a centralized repository for storing and accessing data, enabling users to efficiently manage and manipulate large volumes of data for various applications and purposes.