Here are presented the main components of a computer, not in the way you think you know them, but in a more user-friendly way. Check them out!
The computer display is designed to display text files and more through its computer messages and results. The monitors are of two types: a CRT monitor, using an older technology, but which is used today (the images obtained by directing a beam of electrons in a tube containing an inert gas found at very low pressure. In their way they are confronted with a glow that makes the image plate) and the LCD monitors, based on a liquid crystal monitor technology. The laptops use this kind of technology and they are very useful for the people who travel.
The main unit has inside the motherboard and components that allow the storage and retrieval of the information. On the motherboard it is the microprocessor (that rectangular piece of square inches that is designed to perform all arithmetic and logical operations), the internal memory (which serves to temporarily storage of the programs that are running or waiting, and some data) and sheet extension (which is placed through expansion slots).
The main component through which computer users give commands and enter data by writing is the keyboard. The commands are specific instructions. The mouse is used for the user to give commands. Moving the mouse on a flat surface causes the graphics to move a cursor on the monitor screen. The movement of the mouse causes a certain movement of a small ball placed at the bottom of the mouse. On its turn, the ball puts in motion some cylinders that transmit impulses to the computer. These are interpreted as commands to move the cursor on the screen. When it reaches the right spot of the processor, it behaves accordingly to what the user have said. According to the type of the mouse, it has two or three buttons. Usually, only uses two, left and right button.
The printer lists the documents according to the type of printer, because the printing can be color or black and white. In practice, we use three types of printers: Matrix Printers – have a mechanical type of printing head moving back and forth. The head has, at its turn, several needles, which makes the printing. Between paper and needles, it “moves” a special band which is inked. When these reach the band, the ink is transferred on the paper; Inkjet Printers – their name comes from the fact that they throw a jet of ink to paper. The ink is sprayed through some nozzles (tiny holes). The print mechanism is activated by a crystal that contracts due to an incoming electric impulse and passes the ink through the nozzle and Laser Printers – the printing using laser technology. Initially, an element made of special chemicals, has an animated electric charge on all the surface. Then it conducts a beam of light corresponding to a certain image that will be printed. The charge disappears from the surface affected by light. Further on, a dye is sprayed. This “fills” the areas which have an electric charge. Later it is transferred to the paper by heating creating the image you finally see on paper.
The modem is used to access electronic mail and, in general, the Internet. It is coupled to the computer and a dial-up cable. They are of two kinds: external – are placed outside the central unit and internal – are inside the central unit. They are designed to convert analog signals from the telephone network in the computer as discrete signals, and vice versa.
The scanner is a device that allows to read pages that contain usual images, texts. They are stored in the computer memory and can be sent by electronic mail to be processed and inserted into other documents.
