Text a Computers

A computer is a machine that manipulates data according to a set of instructions. The first electronic computers appeared in the mid-20th century (1940–1945). These were the size of a large room and consumed much power. Those computers used vacuum tubes and electric relays as their electronic elements and were in use throughout the 1950s. In 1960s transistor-based machines, which were smaller, faster, cheaper and more reliable replaced the first computers.

In the 1970s, integrated circuit technology and the creation of microprocessors, such as the Intel 4004, decreased size and cost and increased speed and reliability of computers. The Intel 4004 was powerful enough to become the main unit of many hand calculators at the time. Computing technology rapidly advanced and in the 1980s the first personal computers appeared.

Modern computers on the base of integrated circuits are millions of times more powerful than the first machines. There are computers small enough to build into a watch, which have a watch battery as a source of power. The built-in computers which are present in many devices from MP3 players to aircraft and from toys to industrial robots are however the most numerous.

A Computer-based system consists of two major elements: Hardware and Software. Hardware refers to the physical elements of a computer and consists of three major components: CPU (Central Processing Unit), IO (Input/Output), and Memory.

CPU, in its turn, consists of Arithmetic and Logic Unit(ALU), Control Unit(CU) and Registers. CPU is the main information processor in a computer which performs software instructions, makes calculations and comparisons, provides logical decisions on the base of the Boolean algebra rules.

The Input-Output equipment refers to the communication between an information processing system and the outside world. Common input devices include keyboards and optical scanners; output devices include printers and cathode-ray tube and liquid-crystal display monitors. Devices for communication between computers, such as modems and network interface cards, usually serve for input and output.

Data comes through Input and the CPU processes the data on the base of a program which is in Memory. Memory is a computer data storage system and one of the fundamental components of all modern computers. The information which a computer receives from its input unit is in the main memory or in an auxiliary storage device.

In contrast to hardware software has a non-physical nature. Software is a collection of electronic instructions (routines) and rules that tell the hardware how to perform a task. With the evolution of the Internet, which allows computer users to access and exchange information with other computers personal computers will become as common as the television and the telephone in the household.

Text b The Internet

The Internet is the worldwide network that links millions of computers together via copper wires, fiber-optic cables, wireless connections, and other telecommunications channels. The origins of the Internet reach back to the 1960s. Now the Internet and the World Wide Web are everywhere. In 2008, there were close to 600 million people in the world wide web and in 2009, a quarter of Earth's population used the services of the Internet.

The Internet provides not only answers to different questions but hours of entertainment. The Internet allows people from all over the world to talk to each other. But what exactly are the Internet and the World Wide Web? The terms Internet and World Wide Web are often used in everyday speech without much distinction. However, the Internet and the World Wide Web are not one and the same.

The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks.

The Internet enables or accelerates the creation of new forms of human interactions through instant messaging, Internet forums, and social networking sites. Internet "chat" allows colleagues to stay in touch in a very convenient way. Messages can be exchanged even more quickly and conveniently than via e-mail. The Internet allows people to work together more effectively.

The Internet allows computer users to remotely access other computers and information stores easily, wherever they may be across the world.

In normal use, web browsers, such as Internet Explorer, Firefox, Opera, Apple Safari, and Google Chrome, let users navigate from one web page to another via hyperlinks. Documents on the web may contain any combination of computer data, including graphics, sounds, text, video, multimedia and interactive content including games, office applications and scientific demonstrations.

The World Wide Web has the ability of extreme decentralization of information and data compared to printed encyclopedias and traditional libraries.

With the Web, it is easier for individuals and organizations to present ideas and information to a potentially large amount of people. Many individuals use web logs or blogs, which are updatable online diaries.

E-mail is an important communications service available on the Internet. Pictures, documents and other files can be sent as e-mail attachments.

The prevalent language for communication on the Internet is English.