Computer Hardware

Computer hardware is something that most ordinary users have a very vague understanding of. Yes, when it comes to desktop computer hardware, we can at least see the items of computer hardware (or, more accurately speaking, computer hardware components) surrounding us, but with laptop computer hardware it is a whole another story since in this case all the computer hardware is neatly hidden within this small journal-sized 'box'. What we need to understand is that computer hardware is what our personal computers consist of and what enables them to commit all these tasks we generously assign to them. Every piece of computer hardware is relevant, remember that. Computer hardware monitors, keyboards, the mouse - these are the things we usually understand better, but can you imagine how much stuff there is inside the system unit? Every element of it is a piece of computer hardware, too. The hard disk (usually there are at least two), the motherboard and other things that the possessors of ready-made computers prefer not to think about all belong to the category of computer hardware and are essential to keeping your computer running.

Computer software

Computer software, or just software, is the collection of computer programs and related data that provide the instructions telling a computer what to do. We can also say software refers to one or more computer programs and data held in the storage of the computer for some purposes. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast to the old term hardware (meaning physical devices). In contrast to hardware, software is intangible, meaning it "cannot be touched". Software is also sometimes used in a more narrow sense, meaning application software only. Sometimes the term includes data that has not traditionally been associated with computers, such as film, tapes, and records.

Application software includes end-user applications of computers such as word processors or video games, and ERP software for groups of users.

System software includes operating systems, which govern computing resources. Today large applications running on remote machines such as Websites are considered to be system software, because the end-user interface is generally through a graphical user interface, such as a web browser.

COMPUTER HACKING

Computer hacking is the practice of modifying computer hardware and software to accomplish a goal outside of the creator’s original purpose. People who engage in computer hacking activities are often called hackers. Since the word “hack” has long been used to describe someone who is incompetent at his/her profession, some hackers claim this term is offensive and fails to give appropriate recognition to their skills.
Computer hacking is most common among teenagers and young adults, although there are many older hackers as well. Many hackers are true technology buffs who enjoy learning more about how computers work and consider computer hacking an “art” form. They often enjoy programming and have expert-level skills in one particular program. For these individuals, computer hacking is a real life application of their problem-solving skills. It’s a chance to demonstrate their abilities, not an opportunity to harm other

COMPUTER GENERATIONS

First Generation (1940-1956)   

Vacuum Tubes

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.

Second Generation (1956-1963)

Transistors

Transistors replaced vacuum tubes and ushered in the second generation of computers

The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Second-generation computers moved from cryptic binary machine language to symbolic.

Third Generation (1964-1971)

Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

Fourth Generation (1971-Present)

Microprocessors

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld device.

Fifth Generation (Present and Beyond)

Artificial Intelligence

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come.

COMPUTER DISADVANTAGES

Computer disadvantages are as follows; Violation of Privacy, it is crucial that personal and confidential records stored in computers be protected properly. Impact on Labor Force, although computers have improved productivity and created an entire industry with hundreds of thousands of new jobs, the skills of hundreds of thousands employees are replaced by computers. Health Risks, prolonged or improper computer use can lead to head injuries or disorders. Computer users can protect themselves from health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks. Impact on the Environment, Computer manufacturing processes and computer waste are depleting natural resources and polluting the environment.

COMPUTER VIRUS

Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.
Computer viruses are often spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it.
Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files.
Computer viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.
To help avoid computer viruses, it's essential that you keep your computer current with the latest updates and antivirus tools, stay informed about recent threats, run your computer as a standard user(not as administrator) and that you follow a few basic rules when you surf the Internet, download files, and open attachments.
Once a virus is on your computer, its type or the method it used to get there is not as important as removing it and preventing further infection.

COMPUTER SPEED AND MEASUREMENT UNIT

The time taken to perform any task by computer is called speed of computer. As we know computer can work very fast. It takes only few seconds for calculations that we take hours to complete.

You will be surprised to know that computer can perform millions(1,000,000) of instructions and even more per second. The speed of computer is measured in terms of Mega Hertz(MHZ),Giga Hertz(GHZ),etc. Now a days we have GHZ speed computer Hertz is the unit of frequency that is no of signals per second.

                   The Fractions of seconds are given below.

Unit of time                        Part of second                                         Unit of speed

Milliseconds(ms)               one thousands 1/1,000                             kilo hertz(KHZ)=10*3 HZ

Micro seconds                  one millionth 1/1,000,000                         Mega Hertz(MHZ)=10*6 HZ      

(ms)                                 one billionth 1/1,000,000,000                     Giga Hertz(GHZ)=10*9  HZ  

Nanoseconds(ns)              one trillionth 1/1,000,000,000,000              Tera Hertz(THZ)=10*12HZ   

APPLICATION OF COMPUTER

Computer is used in large areas( such as banking,education,hospital,industries,research,data processing,science and engineering,office,railway,advertisement,communication,libary,simulation,weather forecasting,communication etc.)

1.Banking and Financial Company:Computer are used in this sector for making banking transaction and to keep records,informations of customers.

2.Education:Computer can be used  as teaching learningtools,especially it is used in school for making result, question, handouts and note preparation etc.

3. Industries : industrial research ,budgeting, process control all are computer based.In this feild computer is used for record workdata or to make quotation or to deal with other companies.

4. Hospital: In this section computer  is used for making patients report card and for x-ray.

5. Science and Engineering: Computer is strong tool for every branch of engineering and in science most of the works are done with computer.

6. Offices: It is used in office for checking mails,or to deals with other company.

7. Weather forecasting :Computer programs are used for weather forecasting. The past and present data helps to predict the climate. Now a days, it is the main research in the field of Metrology.

COMPUTER DEFINITION

In the word ''computer'', 'compute' means 'to calculate'.It is the machine developed to perform the tasks of calculating complex tasks of our day-to-day life easily and accurately.Computer is an electronic device.It is a fast and accurate electronic device capable to accept data through input device, store them, process them and give the output or result.It is a powerful machine and can perform large number of tasks as well as store a large amount of data and informations.Computer is a machine capable of solving problems and manipulating data.We can also define it as a device that transforms data as we require.A computer can be defined in terms of its functions i.e.,accept the datas and information,store data,process data as desired and retrive the stored data as and when required and print the result in desired format.

HISTORY OF COMPUTER

The history of computer begins with the development of Abacus before 2500 years ago. It is only a memory-helping device rather than a real calculating machine. The development of Napier's Bones, Slide Rule, Pascaline, Leibnitz Stepped Reckoner, Differential and Analytical Engine that were also called mechanical computers helped to form the computer that we are using now.The first electro mechanical computer was built in 1937 by Howard H. Aiken,a Harvard engineer.It was a large automatic digital computer based on IBM electro mechanical parts.It was also called Harward Mark-I.After that another digital computer was built in 1937-1942 at Lowa state University by John V Atanasoff and Clifford Berry which introduced the ideas of binary arithmetic,regenerative memory and logic circuit.Electronic computers were developed using the ideas of mechanical and electro mechanical computers.ENIAC (Electronic Numerical Integrator and Calculator),EDSAC (Electronic Delay Storage Automatic Computer),EDVAC (Electronic Discrete Variable Automatic Computer) and UNIVAC (Universal Automatic Computer) were developed as electronic computers among which UNIVAC was the most powerful computer.