Introduction of system-

Abstraction for stored set of files, retrieve(received) and update is know as file system. A file system mcludes specified data structures used for it. These data structures are designed to arrange multiple file in flow of bytes. In a file system other abstraction network protocol are also specified. These are designed to access file on remote machine. File system restricts the approach of system data and meta data files. A file system definite the reliability and this the main responsibility of system.

Problems of file system -

• Data redundancy - Same information is available in many files. Like - address of a student is available in various files made for different-different uses
• Data Access difficulty - when a new request comes, than it requires a new program.Because at every time new program is not available to fulfill the new request , so for new request writing of new program is require.
• Data is isolated - Data is kept in different-different files, in different-different formats.
• Mutiple users can not use data at a time because it is difficult to observes in parallel request.
• security in database in less
• Integrity issues - Problems in database 
• Benefits of file system-

1. ​Easy design with single application.
2. Optimized collection based on single application.
3. Efficient in presentation.

Hierarchy of data - Data stored in computer system can be view by following method and than we can define the Database Management System. Data is organized is logical form as follows-​

• Bits
• Field 
• Record 
• Files 
• Database

Bit- A bit is the smallest unit to represent the data (value of a bit can be 0  or 1)

Field- A Field is a group of characters. A data field represents a single attributes of a entity (object, person, place or event).

A record has all the field, and every field is a attribute of a entity.

Fiels- Collections of related records. A primary key is a field in the file which identifies a data uniquely in a file.

Now we can define Database Managment System. As it can identified by it's name, Database Managment system is from by two words - Data base and managed system.

Database- What is database? To understand this, we start from data, which is the basic building block of any DBMS.

Data- Fact, figures, numbers which do not have any specific meaning. (like 2, xyz,19 etc.)

Record- Collection of related data items.

File- Collection of related records.

Database- Collection of interrelated data or data files (Relational database).(Imp.)

Thisn is the collection of intrrelated data which can be information about an organization and set of application program can be used to reach to this collection of information.

Managment System- Management System has a set of rules and processes which helps to create database, update, rearrange it. It helps to add or remove or update data items in database