Types of network

Peer-to-Peer Networking 

This is a simple network configuration that requires some basic know-how to set up. Each of the interconnected machines share dual capability and responsibility on the network. That is to say, that each machine serves a dual purpose or role, i.e. they are both clients and servers to some extent. The server capability of the machines is very basic. The services provided by each, is no more than the ability to share resources like files, folders, disk drives and printers. They even have the ability to share Internet access.

Advantages

  · Easy to install and configure.

  · No dedicated server required.

  · Users control their own resources.

  · Inexpensive to purchase and operate.

  · No specialist software required.

  · No dedicated administrator to run the network required.

 

Client/Server Networks 

Server based networks, or client/server networks as they are properly called, has a machine at the heart of its operations called the server. A server is a machine that provides services over a network by responding to client requests. Servers rarely have individuals operating it, and even then, it is usually to install, configure or manage its capabilities. The server's essential role on the network is to be continuously available to handle the many requests generated by its clients. Server-based networks provide centralized control of the entire network environment. The computer systems used for this role are generally more powerful than end-user machines, incorporating faster CPUs, more memory, larger disk drives and other drive types installed, like a tape drive for backup purposes. These are required, because servers are dedicated to handling multiple simultaneous requests from their client communities.

 Server based networks provide centralized verification of user accounts and passwords. Only valid account name and password combination are allowed access to the network. Client/Server networks typically require a single lo-gin to the network itself, meaning that users need to remember long password lists to access various resources. Concentrations of resources on a single server, mean that they are easier to find, as opposed to the peer-to-peer model, were resources were distributed throughout the network since they were attached to multiple machines. The server being a central data repository, means that not only is data more accessible to users, but it also makes life much easier in terms of performing backups, since the data is in a location know to the administrator.

Advantages

  · Centralized user accounts, security and access controls simplify network administration.

  · More powerful equipment means more efficient access network resources.

  · Single password lo-gin, means access to all resources.

  · Supports greater numbers of users, or networks where resources are heavily used. 

 

 

 

Computer networks

It is simply a group of interconnected computers. Most people working in office with more than a couple of computers will be using some form of network. As networks become easier to setup and maintain more home users are also setting up networks to share resource such as disk space, printers, Internet connections and access to software.
A network is basically two or more computers connected through a cable or wire which share resources. Network software controls how the computers communicate.
There are dozens of different types of networks which are impossible to cover in an introduction article. This article focuses on home and small business networks using some version of the Window operating system.
To connect computers each of the computers needs a network card with a connection that allows a cable to be connected to it. Computers can be connected directly through a bi-directional cable or through an other piece of hardware called a hub. The hub then connects all the computers in your local network together. Both solutions cost about the same but a hub allows more than two computers to connect. A hub can also be used to connect two local area networks together to create a wide area network.

Software Layers

Software is part of computer which is intangible. It tells what a computer supposed to carry out and how to do it. And, it drives hardware.
Software is divided in to three categories:
1. System software.
2. Application software.
3. Programming language.
System software controls and maintains the operations of the computer and its devices.
Application software makes user more productive and assist them with their tasks.
Programming language enables people to communicate instructions to a computer.

 

StorageStorage

Storage holds data, instructions and information for future.
Types of storage:
Removable Hard Drive – This is a disk drive in which a plastic or metal case surrounds the hard drive. It can be inserted and removed just like a floppy disk. It holds about 2 GB of data.
Internet Hard Drive – This one is a service on the Internet that provides storage space to computer users. This service offers about 25 MB of space, but it could be more, depending on the service type.
Flash Drive – This a storage device that comes in many colors and has a stick shape to it. They are very small in size, but they can hold anywhere between 256 MB and 3 GB of material on them.

PC Card – This is a thin credit card size device that fits into a PC card slot, usually on a notebook computer. This card simply adds storage to most notebooks.
Smart Cards – These are the size of an ATM card. When inserted into a smart card reader, they can read and update data for you.
Storage Tape – This one is a magnetically coated ribbon of plastic, capable of storing large amounts of data at a very low cost. Usually, storage tapes are a little bigger than audio tapes. Older computers used tape and tape drives, but even today, some people still back their systems up with storage tape. These tapes hold between 20 GB to about 110 GB of data. An external tape drive can be purchased separately as well, but those are even harder to find.
Miniature Mobile Storage Media – This is used mostly with hand held computers and digital cameras.
Memory Stick – This is a rectangular shaped disk that is used mostly with digital cameras and notebook computers. They hold approximately 128 MB as well.
Micro Drive – This is a square disk that has 1 GB of space and is used with digital cameras and hand held computers.
Smart Media Disc – This is a square disk that has 2 MB to about 128 MB of space on it. It’s used with digital cameras, hand held computers and photo printers.
There you go! These are just some of the storage devices that are available today. So, the next time you want to save something that takes up a large amount of space on your hard drive, think twice about it and consider using one of these storage devices instead. One of these devices could save you a lot of space on your hard drive and keep your system running at its best!
There are so many but i mention just some of them. 

Computer hardware basics

The hardware are the parts of the computer itself including the Central Processing Unit (CPU) and related microchips and micro-circuitry, keyboards, monitors, case and drives (hard, CD, DVD, floppy, optical, tape, etc...). Other extra parts called peripheral components or devices include mouse, printers, modems, scanners, digital cameras and cards (sound, color, video) and so on. Together they are often referred to as a personal computer.

History of computer

First Generation (1941-1956)

World War gave rise to numerous developments and started off the computer age. Electronic Numerical Integrator and Computer (ENIAC) was produced by a partnership between University of Pennsylvania and the US government. It consisted of 18,000 vacuum tubes and 7000 resistors. It was developed by John Presper Eckert and John W. Mauchly and was a general purpose computer. "Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 with a memory to hold both a stored program as well as data." Von Neumann's computer allowed for all the computer functions to be controlled by a single source.
Second Generation Computers (1956-1963)
The invention of Transistors marked the start of the second generation. These transistors took place of the vacuum tubes used in the first generation computers. First large scale machines were made using these technologies to meet the requirements of atomic energy laboratories. One of the other benefits to the programming group was that the second generation replaced Machine language with the assembly language. Even though complex in itself Assemly language was much easier than the binary code.


Third generation was during 1964-1974 in this year the size of computer has reduced.

Fourth Generation (1971-Present)

Fourth Generation computers are the modern day computers. The Size started to go down with the improvement in the integerated circuits. Very Large Scale(VLSI) and Ultra Large scale(ULSI) ensured that millions of components could be fit into a small chip. It reduced the size and price of the computers at the same time increasing power, efficiency and reliability. "The Intel 4004 chip, developed in 1971, took the integrated circuit one step further by locating all the components of a computer (central processing unit, memory, and input and output controls) on a minuscule chip.
Fifth Generation (Present and Beyond)

Fifth generations computers are only in the minds of advance research scientists and being tested out in the laboratories. These computers will be under Artificial Intelligence(AI), They will be able to take commands in a audio visual way and carry out instructions. Many of the operations which requires low human intelligence will be performed by these computers. 
Characteristic of fifth generation computer
1) The fifth generation computers will use super large scale integrated chips.
2) They will have artificial intelligence.
3) They will be able to recognize image and graphs.
4) Fifth generation computer aims to be able to solve highly complex problem including decision making, logical reasoning.
5) They will be able to use more than one CPU for faster processing speed.
6) Fifth generation computers are intended to work with natural language.

 

What is computer?

 

Computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. Conventionally a computer consists of some form of memory for data storage, at least one element that carries out arithmetic and logic operations, and a sequencing and control element that can change the order of operations based on the information that is stored. Peripheral devices allow information to be entered from an external source, and allow the results of operations to be sent out.
Computer Operation.

Basic operations which computer can perform:

• Input
• Processing
• Output
• Storage

Others Devices: Communication