Рубрика:
86
and radio. This has transformed everyday life as much as engines and motors.
There are many machines developed to handle the information, for example
television cameras to record pictures, transmitters to send these pictures to
television receivers in people’s homes.
The ease of using machines also varies and is not always related to their
complexity. For example, some, like refrigerators, can work untended, and
little skill or training is required to use a television set or a tin-opener; whereas
considerable aptitude, instruction and practice is needed to fly an airplane or
use a potter’s wheel. The amount of skill and training required might depend
on the circumstances of use – driving a motorcar on a country road is a skill
relatively easily acquired compared to driving a racing car on a grand prix
circuit. Knowledge of the principles behind the operation of a machine may be
useful. It is possible to drive a car without knowing anything about what
happens under the bonnet, although one can probably drive better for knowing
something about mechanics.
Computers are machines, which handle information, and they are based on
relatively simple principles. Knowledge of these principles helps one to
understand computers and make better use of them.
Computers which deal with numerical information can be divided into three
classes: (1) digital, in which the representation of numbers and the calculations
on them are performed by counting processes (e. g. by counting teeth on gear
wheels or counting electrical impulses); (2) analogue, in which the representation
of numbers and the calculations on them are performed my measuring processes
(e. g. in electronic computers by measuring voltages); and (3) hybrid, in which
both kinds of process are used. Nowadays the word computer, unless qualified,
normally means ‘electronic digital computer’; ‘electronic’ because in most
computers electronic processes have replaced all others because of their speed,
reliability and cheapness, “digital” because the exactness of digital processes
implies a greater potential for accuracy.
(2430 t. un.)
The internet
The Internet, a global computer network that embraces millions of users all
over the world, began in the US in 1969 as a military experiment. It was designed
to survive a nuclear war. Information sent over the Internet takes the shortest path
available from one computer to another. Because of this, any two computers on
the Internet will be able to stay in touch with each other as long as there is a single
route between them.
