This document defines data communication and its components. It discusses protocols that establish communication rules between devices, including TCP, UDP, and IP. It also describes the three main data flow modes: simplex for one-way transmission; half duplex for two-way transmission but not simultaneously; and full duplex for simultaneous two-way transmission, giving examples for each. Key parts of data communication systems are identified as the sender, receiver, transmission medium, and protocols that govern message exchange.

1. Data communication
Data communications and its type:

2. Defination of data
communications:
The exchange of data between two or more networked or connected
devices.
EX: mobile phone,laptop etc
sender reciever
Transmission
medium
messsage
protocol

3. 1: PROTOCOAL:
 It is set of rules that need to be followed by the communicating parties in
order to have successful and reliable data communication.
 EXAMPLE
 Internet and HTTP
 TCP: transmission control protcol
 UDP: user data gram protocol
 IP: internet protocol
Components of data communication

4. 2: Sender
The device that send the message is called sender.
3:RECEIVER:
The device that receive the message is called receiver.
4: Transmission medium:
The physical path between sender and receiver is called transmission
medium.

5. DATA FLOW IN COMMUNICATION:
1: SIMPLEX MODE:
It is a communication mode in which only one signal is transmitted. And it always
goes in the one direction.
 The transmitter and the receiver operate on the same frequency.
 EXAMPLE: monitor, keyboard.
Sender reciever

6. 2: HALF DUPLEX MODE:
 In half duplex mode sender can send the data and receiver can receive the
data but not at one time.
 It is two way directional communication but not at a time.
EXAMOLE: walkie-talkie.
Sender Reciever

7. 3: FULL DUPLEX MODE:
 In full duplex mode sender can send the data and also can receive the data
simultaneously.
 EXAMPLE : telephone
Sender reciever