Database normalization was first proposed by Dr. Edgar F Codd as an integral part of RDBMS in order to reduce data redundancy and improve data integrity. These rules are known as E F Codd Rules.

SQL server, Oracle, MySQL, MariaDB, SQLite.

DBMS Supports Transactions : It allows us to better handle and manage data integrity in real world applications where multi-threading is extensively used.

Data Consistency means that data values are the same at all instances of a database.

Entity Relationship Model (ER model):
(i) In this database mo-ad., relationship are created by dividing the object into entity and its characteristics into attributes.
(ii) It was developed by Chen in 1976. This model is useful in developing a conceptual design for the database.
(iii) It is very simple and easy to design logical view of data. The developer can easily understand the system by looking at ER model constructed.

The Database Management System can be divided into five major components as follows:
(i) Hardware
(ii) Software
(iii) Data
(iv) Procedures / Methods
(v) Database Access Languages

Advantages of DBMS:
(i) Segregation of application program
(ii) Minimal data duplication or Data Redundancy
(iii) Easy retrieval of data using the Query Language
(iv) Reduced development time and maintenance

Database Administrators:
Database Administrator or DBA is the one who manages the complete database management system. DBA takes care of the security of the DBMS, managing the license keys, managing user accounts and access etc.
Application Programmers or software Developers:
This user group is involved in developing and designing the parts of DBMS.
End User:
All modern applications, web or mobile, store user data. Applications are programmed in such a way that they collect user data and store the data on DBMS systems running on their server. End users are the one who store, retrieve, update and delete data.
Database designers:
Database designers are responsible for identifying the data to be stored in the database for choosing appropriate structures to represent and store the data.

Object model stores the data in the form of objects, attributes and methods, classes and inheritance. This model handles more complex applications, such as Geographic information System (GIS),sdentific experiments, engineering design and manufacturing. It is used in file Management System. It represents real world objects, attributes and behaviors. It provides a clear modular structure. It is easy to maintain and modify the existing code.

An example of the Object model is Shape, Circle, Rectangle and Triangle are all objects in this model
(i) Circle has the attribute radius.
(ii) Rectangle has the attributes length and breadth.
(iii) Triangle has the attributes base and height.
(iv) The objects Circle, Rectangle and. Triangle inherit from the object Shape

The Database Management System can be divided into five major components as follows:
(i) Hardware
(ii) Software
(iii) Data
(iv) Procedures / Methods
(v) Database Access Languages

(i) Hardware: The computer, hard disk, I/O channels for data, and any other physical component involved in storage of data
(ii) Software: This main component is a program that controls everything. The DBMS software is capable of understanding the Database Access Languages and interprets into database commands for execution.
(iii) Data: It is that resource for which DBMS is designed. DBMS creation is to store and utilize data.
(iv) Procedures/Methods: They are general instructions to use a database management system such as installation of DBMS, manage databases to take backups, report generation, etc
(v) DataBase Access Languages: They are the languages used to write commands to access, insert, update and delete data stored in any database.
Examples of popular DBMS: Dbase, FoxPro

Characteristics of Database Management System