The process of creating, implementing and maintaining the enterprise data in a system is known as Designing of databases.

(i) XAMPP is a free and open source package.
(ii) It was developed by Apache.
(iii) It is a software platform for MySQL, PHP and Peri programming languages.

In relational database model,
(i) Table is defined as the collection of data organized in terms of rows and columns.
(ii) Table is the simple representation of relations. The true relations cannot have duplicate rows

The features of RDBMS are
(i) High Availability
(ii) High Performance
(iii) Robust Transactions and support
(iv) Ease of management
(v) Less cost

(i) Data Duplication
(ii) High Maintenance
(iii) Security

(i) Indexed method
(ii) Random Method
(iii) Sequential Method

Definition:
(i) A database management system (DBMS) is system software for creating and managing databases.
(ii) The DBMS provides users and programmers with a systematic way to create, retrieve, update and manage data.

Advantages:
(i) High Availability
(ii) High Performance
(iii) Robust Transactions and Support
(iv) Ease of Management
(v) Less Cost

In ER Model, relationship exits between two entities.
Types :
(i) one-to-one Relationship,
(ii) one-to-many Relationship,
(iii) many-to-many Relationship.

S.No	SQL	MySQL
1.	SQL is a structured query language.	MySQL is a database software.
2.	SQL is used to query and operate a database system.	MySQL allows data handling, storing, modifying, deleting etc.

COMMIT Command is used to make permanent changes done by transaction.

ACID Properties :
(i) The acronym stands for Atomicity, Consistency, Isolation and Durability.
(ii) Atomicity follows the thumb rule "All (or) Nothing" while updating the data in database for the user performing the update operation.
(iii) Consistency ensures that the changes in data value to be constant at any given instance. Isolation property is needed during concurrent transaction.
(iv) Durability is defined as the system is ability to recover all committed transactions during the failure of storage or the system

DDL Commands :
(i) CREATE :
Syntax : CREATE database database name; 
(ii) DROP
Syntax : DROP database databasename;
DML Commands:
(i) INSERT 
Syntax: INSERT INTO table name (column 1, column 2, column 3) VALUES (value 1, value 2, value 3);
(ii) UPDATE
Syntax: UPDATE tablename
SET column 1 = "new value"
Where column2="value2";

i). Data Duplications : Same data is used be multiple resources for processing, thus created multiple copies of same data wasting the spaces.
ii). High Maintenance : Access control and verifying data consistency needs high maintenance cost.
iii). Security : Less security provided to the data.

Data models define how the logical structure a database is modeled. Data models define how data is connected to each other and how they are  processed andstored inside the system
Types of Data Model :
1) Hierarchical database model 
2) Network model 
3) Relational model 
4) object oriented database model