Data processing is any computer process that converts data into information or knowledge. The processing is usually assumed to be automated and running on an a computer. Because data are most useful when well-presented and actually informative, data-processing systems are often referred to as information systems to emphasize their practicality.

A variable is unique place in memory for storing data while executing the program.Variables in JAVA have more functionality as compared to C and C++.JAVA introduce the String Class for manipulating the strings data.Also JAVA introduced the boolean data type.Below is the table for discribing the data types and lengths of each:-

Declaring the Variables:-

User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, sometimes known as datagrams, to other hosts on an Internet Protocol (IP) network without requiring prior communications to set up special transmission channels or data paths. UDP is sometimes called the Universal Datagram Protocol.

There are four possible combinations of data and signal types:

1. Analog data, analog signal;
2. Digital data, analog signal;
3. Analog data, digital signal;
4. Digital data, digital signal.

In digital telecommunication, the bit rate is the number of bits that pass a given point in a telecommunication network in a given amount of time, usually a second.Although kilobits and Megabits where 1kb (1 kilobit) = 1024 bits and 1Mb (1 Megabit) = 1024 kilobits, bitrate calculations use standard metric values for these prefixes, meaning 1kb = 1000b and 1Mb = 1000kb.

Data Communications

Data Communications is the transfer of data or information between a source and a receiver.The purpose of Data Communications is to provide the rules and regulations that allow computers with different disk operating systems, languages, cabling and locations to share resources. The rules and regulations are called protocols and standards in Data Communications.

DCL language is used to control access to data in a database.This language defines the access permissions for users and groups on the pieces of data in database.E.g We use commands to provide permissions for individual user to make SELECT statements for data table.

Examples of DCL commands include:

•     GRANT to allow specified users to perform specified tasks.
•     REVOKE to cancel previously granted or denied permissions.

The following privileges can be GRANTED TO or REVOKED FROM a user or role:

DML is used by computer programs database users to retrieve, insert, delete and update data in a database.Currently the most popular data manipulation language is that of SQL, which is used to retrieve and manipulate data in a Relational database.

Basic Data operations are:-

1. Select
2. Insert
3. Update
4. Delete

The ability to modify a scheme definition in one level without affecting a scheme definition in a higher level is called data independence.

Data independence is of two types:-

Network model can be seen as refinement of hierarchical model.Hierarchical model provide only 1:M relationship(Means one parent and multiple childs) but now in network model it provide M:M relationship(Many To Many relationship means each child can have multiple parents and parents can have multiple childs as well).The network model is a database model conceived as a flexible way of representing objects and their relationships.

• The network model allows each record to have multiple parent and child records, forming a lattice structure.