Communication Networks:
It is an interconnection of different locations through a medium that enables people to send and receive Information.
Data processing Life Cycle (DPLC):
It is a collection of steps required to convert data into information.
Steps of Data Processing Life Cycle:

• Input
• Process
• Output
• Storage

Types of Environment:

• Centralized Environment
• Distributed Environment

Centralized Environment:
? It has a large central system with terminals as clients.
? All processing is done by the large systems and Terminals are Only for Input & Output
Characteristics of Centralized Environment:
? All loads are On the Server.
? All Clients deliver a request to the server
? Client has only a keyboard & a Mouse.
? It is a time wasting
? Client has no processing Power.

Distributed Environment:
? In this environment client has their own processing power.
? Central systems / Servers are only used for storage.
Characteristics of Distributed Environment:
? Client has the Processing Power.
? Client can locally process their Information.
? It is a time saving.
? Load on the server is less.

Networks:
Networks are groups of computers connected together by some type of media to allow them to share the information.
Clients:
Clients send the request to the server.
Server:
Server fulfills the request of Client.
Types of Networks:
There are three types of Networks

• LAN
• WAN
• MAN

LAN:
? The smallest Network size is LAN.
? LAN?s are normally contained in Buildings.


a) High Speed
b) Inexpensive Price
c) Smallest error counts
MAN:
? MAN is a group of LAN?s
? MAN is slower than LAN
? Have Few errors of the Network
WAN:
? WAN is the Largest Area Network
? WAN Can Connect Networks across Cities, States, or Even in the Whole World.
? It is Much Slower than LAN
Components of Computer:

• Input Devices
• Output Devices
• System Unit
• Storage Devices
• Communication Devices

Input Devices:
A hardware Component used to enter the data & instruction to the computer is called input device.
Output Devices:
A hardware Component used to display the information to USER is called Output Device.
System Unit:
It is box that contains different electronic components of Computer.
v It Protects the Internal Components from Damage.
v The Electronic circuits in the system unit are connected to the Motherboard
Storage Devices:
The hardware component used to store the data and Information Permanently
Communication Devices:
The hardware component used to communicate & Exchange data, instructions & Information with other devices are called communication Devices.
E.g. Modem:
It enables computer to communicate with other computers via telephone lines & cables.