• A database management system is a software designed to assist in maintaining and utilizing large collection of data.

•  The alternative to use a DBMS is to store the data in files and write application specific to manage it.
• DBMS allows users to create their own databases as per requirement.
•  It provides an interface between the data and the software application.

Advantage of DBMS

• Data independence. 
• Efficient data access
• Data integrity and security
• Data Administration 
• Concurrent access and data recovery
• Reduce application development time

Types of DBMS 

1. Hierarchical DBMS
2. Network DBMS
3. Relational DBMS
4. Object Oriented

1.Hierarchical DBMS

• In Hierarchical database, model data is organized in a tree like structure.
• Data is stored hierarchically (top down or bottom down ) format .
• Data is represented using a parent child relationship.
• In hierarchical DBMS parent may have many children,but children have only one parent.

2.Network DBMS

• The network database model allow each child to have multiple parents.
• It helps you to address the need to model more complex relationship like many to many relationship.
• In this model,entities are organized in a graph which can accessed through several paths.

3.Relational DBMS 

• Relational DBMS is the widely used DBMS model in the industries because it is one of the easiest.
• Relational DBMS based on the normalization data in the row and column of the tables.
• It is stored in a fixed structures and manipulated using SQL.

4.Object Oriented 

• In object oriented model data data stored in a form of objects. 
• The structure we called is class we stored data within the class.
• It define a database as a collection of objects which store both data members values and operations.

1. File Form      

• SQL server database have three types of file:

a.Primary File:-       

• The primary data file contains the startup information for the database and point to the others file in database.
• User data and object can be stored in this file or secondary data file.
• Every database has one primary data file.
• The recommended file name extension for primary data file is ".mdf ".         

b.Secondary File:-      

• Secondary data files are optional,are user defined and store user data.
• Secondary files can be  used  to spread data across multiple disk by putting each file on a different disk drive.
• If a database exceeds the maximum size for a single windows file you can use secondary data files so the database can continue grow.
• The recommended file name extension for secondary data files is ".ndf".

c.Transaction Log:-

• The  transaction log files hold the log information that is used to recover the database.
• There must be at least one log file for each database.
• The recommended file name extension for transaction log is ".ldf".

2.Table Form

• SQL table is a collection of data which is organized in terms of rows and columns.
• In DBMS,the table as known as relation and row as a tuples.
• Table is a simple form of  data storage.A table  is also convenient representation of relation.
• Tables contains multiple records (Rows and Columns ).

What is Database

• A database is a systematic collection of data .
• Database support storage and manipulation of data.
• Database make data management easy.

Table And Record

• A table in a relational database is a predefined format of rows and column that define an entity.
• Each column contains a different type of attribute and each row corresponds to a single record.
• Each table is provided with a name.