Network Basic

CLASSIFICATION OF NETWORK

Local Area Network(LAN)
-is a network connects computers and devices in a limited geographical area.
-Wireless LAN (WLAN) is a LAN uses no physical wires

Advantages Of LAN:
-Easy to share devices
-Easy to share data
-Low cost

Disadvantages Of LAN:
-Covered a limited area
-Power need to be on all the time for a good LAN
-Can reduce speed for each computer if all computers running at once


Metropolitan Area Network(MAN):
-Is a high speed network that connects local area network in a metropolitan area and handles the bulk of communications activity across that region
-Campus Area Network(CAN) is a type of MAN that made up of an interconnection of local area network(LAN's) within a limited geographical area

Advantages of MAN:
-efficiency and shared access
-All computer-owning residents of an area have equal ability to go on line

Disadvantages of MAN:
-Costly
-Security problems
-Connection can become quite slow


Wide Area Network(WAN):
-Is a network that covers a large geographic area using a communications channel

Advantages Of WAN:
-Increased efficiency
-Ease of communication
-Low costs

Disadvantages Of WAN:
-Security problems
-Training costs
-Maintenance problems


Comparison between LAN,MAN &WAN

LAN: (local area network) A group of computers that share a common connection and are usually in a small area or even in the same building. For example an office or home network. They are usually connected by Ethernet cables and have high speed connections. If it was a wireless setup it would be called a WLAN, which would have a lower connection speed. 

MAN: (metropolitan area network) This is a larger network that connects computer users in a particular  geographic area or region. For example a large university may have a network so large that it may be classified as a MAN. The MAN network usually exist to provide connectivity to local ISPs, cable tv, or large corporations. It is far larger than a LAN and smaller than a WAN. Also large cities like London and Sydney, Australia have metropolitan area networks.

WAN: (wide area network) This is the largest network and can interconnect networks throughout the world and is not restricted to a geographical location. The Internet is an example of a worldwide public WAN. Most WANs exist to connect LANs that are not in the same geographical area. This technology is high speed and very expensive to setup.

All about NETWORK!!!

NETWORK..

WHAT IS A NETWORK???

A network is a collection of computers and devices connected together via communications devices and transmission media

ADVANTAGES OF USING NETWORK??

• Facilitating communication
• Sharing hardware
• Sharing software
• Transferring funds

DISADVANTAGES OF USING A NETWORK??

• Viruses
• Network failure
• Slow service
• Cost
• Expert support required

Network Architecture..

The design of computers, devices, and media on a network is sometimes called the network architecture

Peer to Peer

P2P describes an internet network on which users access each other's hard disks and exchange files directly over the internet..

Client Server

One or more computers act as a server, and the other computers on the network request services from the server..

• Client

----> clients are other computers and mobile devices on the network that rely on the server for its resources

• Server

----> SERVER, sometimes called a host computer, controls access to the hardware, software, and other resources on the network and provides a centralized storage area for program, data and information...

NETWORK TOPOLOGY 

What is topology????

A network topology refers to the layout of the computers and devices in a communication network.

It refers to both the physical and logical layout of a network...

Layout of network..

Physical Topology..

=> The arrangements of a cabling is the physical topology

Logical Topology

=> The path that data travels between computers on a network is the logical topology..

Types of network topology..

Three commonly used network topologies are :

• Bus

• The bus is the physical cable that connects the computers and other devices
• The bus in a bus network transmit data, instructions, and information as a series of signal
• Those signals are sent as electrical pulses that travel along the length of the cable in all directions
• Each devices is connected to the single bus cable through T-Connector.
• A terminator is required at each end of the bus cable to prevent the signal from bouncing back and forth on the bus cable.
• When a sending device transmits data, the address of the receiving device is included with the transmission.
• If the device address does not match the intended address for the data, the device ignores the data.
• If the data does match the device address, the data is accepted.
• All devices receive the data but only the receiving device accept them.

STAR

• All the computers and other devices on the network connect to a central device, thus forming a star
• Two types of devices that provide a common central connection point to all the other devices on the network are a hub and a switch.

RING

• On a ring network, a cable forms a closed loop(ring) with all computers and devices arranged along the ring.
• Data transmitted on a ring network travels from device to device around the entire ring, in one direction (clockwise or counterclockwise)
• Token passing is one method for sending data around a ring
• Each device takes a turn sending and receiving information through the use of a token
• The token along with any data is sent from the first device to the second device which extracts the data addressed to it and adds any data it wishes to send.
• Then second device passes the token and data tothe third device, etc. until it comes back around to the first device again. 
• Only the device with the token is allowed to send data . All other devices must wait for the token to come to them.

Computer System

What is a computer system?????

a system of one or more computers and associated software with common storage.

Latest desktop with latest operating system (Windows 8)

List of computer system:

Input

• Any data and instruction entered into memory of 

computer

Output

• Data that has been processed into a useful form.

Process

• Transform an input data flow into an output data 

flow.

Storage

• Hold data instructions and information for future

use.

Information processing cycle6

 Information processing cycle is the series of 

input, process, output and storage 

activities.

 Computer process data (input) into 

information (output)

 Computer holds data, information and 

instructions in storage for future use 

Information processing

Component of computer(Hardware)

A computer contains many electric, electronic, and 

mechanical components known as hardware.

-Input Device - Allows you to enter data and instructions into a computer

-Output Device - Hardware component that conveys information to one or more people

-System Unit - Case that contains the electronic components of the computer that are used to process data             

-Storage Device - Records (writes) and/or retrieves (reads) items to and from storage media 

-Communication Devices - Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices

Examples of Input Devices

Examples of Output Devices

Motherboard

a printed circuit board containing the principal components of a computer or other device, with connectors into which other circuit boards can be slotted.

Every motherboard has connectors and slots to connect all the remaining parts of CPU. here the list of all the slot and connector of motherboard.

• CPU Socket
• North Bridge
• South Bridge
• RAM Slots
• AGP Slot
• PCI Slots
• CNR Slot
• Floppy Connector
• Primary and Secondary IDE Connectors
• SATA connectors
• Power Connector
• BIOS
• CMOS battery
• Ports

CPU Socket:

CPU Socket or Processor Socket. Which is used to install or insert the processor. we have two types of sockets. LIF sockets and ZIF socket. LIF stands for Low Insertion Force, this is the old model sockets and ZIF stands for Zero Insertion Force, this is the present model sockets. 

 

LIF socket or slot type processor socket

ZIF socket or PGA sockets

North Bridge:

North Bridge is always near the processor socket. which is one of the important component of a motherboard. It is a focal Point of Motherboard and It is also called as Memory Controller Hub. North Bridge interconnects Processor socket, RAM slots and AGP slot. here Gigabyte chip is north bridge it is near Processor socket.

South Bridge:

North bridge and south bridge are the two main poles of a motherboard. South Bridge interconnects Primary and Secondary IDE interfaces, SATA connectors, Floppy Drive Connector, PCI slots and BIOS. 

RAM Slots: 

RAM slots are used to insert RAMs. there are so many types of ram slots. they are SD ram slots, DDR ram slots, DDR2 and DDR3 ram slots. SD stands for synchronize Dynamic and DDR Stands for Double Data Rate.

AGP slot:

AGP slots are used to insert or install AGP Cards. AGP full form is Accelerated Graphics Port. This slot is for graphics and 3d gaming purpose. it is always beside the PCI slots

PCI slots:

PCI slots are used to Insert or install Add-on cards, such as LAN cards, Sound cards, Capture cards and TV tuner cards. PCI full form is Peripheral Component Interconnect.

Floppy Drive Connector:

Floppy Drive Connector is used to connect floppy drives. It supports two floppy drives. so that A and B drives are reserved for two floppy drives in My computer. it has 32 pins. 

Primary and Secondary IDE Interfaces:

Primary and Secondary IDE interfaces are also called as IDE connectors or PATA connectors. IDE full form is Integrated Device Electronics. it supports IDE devices, such as Hard disks and CD and DVD drives.

SATA Connectors:

SATA connectors are also called as Serial ATA connectors. SATA full form is Serial Advanced Technology Attachment. These are connect with serial ATA devices, such as Hard disk drives and CD or DVD drives.

Power Connector:

This power connector is ATX power connector. it has 20 or 24 pin connector. mother takes the power from this connector to work.

BIOS:

BIOS stands for Basic input and Output system. This is also one of the important chips. it conducts the POST (Power On Self Test).

CMOS battery:

There is a battery in the motherboard, which is used to power the south bridge and the BIOS to save the setting, data and time.

 Ports:

Ports are used to connect input and output devices. they are attached and come with motherboard and they are in backside of CPU.

Memory

Internal storage areas in the computer. The term memory identifies datastorage that comes in the form of chips, and the word storage is used for memory that exists on tapes or disks. Moreover, the term memory is usually used as a shorthand for physical memory, which refers to the actual chips capable of holding data. Some computers also use virtual memory, which expands physical memory onto a hard disk.

Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM. You can think of main memory as anarray of boxes, each of which can hold a single byte of information. A computer that has 1 megabyte of memory, therefore, can hold about 1 million bytes (orcharacters) of information.

There are several different types of memory:

RAM (random-access memory): This is the same as main memory. When used by itself, the term RAM refers to read and writememory; that is, you can both write data into RAM and read data from RAM. This is in contrast to ROM, which permits you only to read data. Most RAM is volatile, which means that it requires a steady flow of electricity to maintain its contents. As soon as the power is turned off, whatever data was in RAM is lost.

ROM (read-only memory): Computers almost always contain a small amount of read-only memory that holds instructions for starting up the computer. Unlike RAM, ROM cannot be written to.

PROM (programmable read-only memory): A PROM is a memory chip on which you can store a program. But once the PROM has been used, you cannot wipe it clean and use it to store something else. Like ROMs, PROMs are non-volatile.

EPROM (erasable programmable read-only memory): An EPROM is a special type of PROM that can be erased by exposing it to ultraviolet light.

EEPROM (electrically erasable programmable read-only memory):An EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge.

Storage

Computer data storage, often called storage or memory, is a technology consisting of computer components and recording mediaused to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but larger and cheaper options farther away. Often the fast, volatile technologies (which lose data when powered off) are referred to as "memory", while slower permanent technologies are referred to as "storage", but these terms can also be used interchangeably. In the Von Neumann architecture, the CPU consists of two main parts:control unit and arithmetic logic unit (ALU). The former controls the flow of data between the CPU and memory; the latter performs arithmetic and logical operations on data.

Application software

Application software, also known as an application, is computer software designed to help the user to perform singular or multiple related specific tasks. Examples include enterprise software, accounting software, office suites, graphics software, and media players.

Type of software:

-Open source software

-Packaged software

-Shareware

-Freeware

-Webapplication

-Public-domain software

-Custom software

System software

system software (or systems software) is computer software designed to operate and control the computer hardware and to provide a platform for running application software.^[1][2]

System software includes the following:

• The operating system (prominent examples being z/OS, Microsoft Windows, Mac OS X and Linux), allows the parts of a computer to work together by performing tasks like transferring data between memory and disks or rendering output onto a display device. It also provides a platform to run high-level system software and application software.
• Utility software helps to analyze, configure, optimize and maintain the computer.
• Device drivers such as computer BIOS and device firmware provide basic functionality to operate and control the hardware connected to or built into the computer.
• Window systems are components of a graphical user interface (GUI), and more specifically of a desktop environment, which supports the implementation of window managers, and provides basic support for graphics hardware, pointing devices such as mouse, and keyboards. The mouse cursor is also generally drawn by the windowing system.

In some publications, the term system software also includes software development tools (like a compiler, linker or debugger).^[3]

In contrast to system software, software that allows users to do things like create text documents, play games, listen to music, or surf the web is called application software.

Example of operating system

Example of utility program-a type of system software that allows user to perform maintenance-type tasks.