What is computer hardware ?
Not everybody has exactly the same hardware. But those of you who have a desktop system, probably have most of the components shown in that same figure. Those of you with notebook computers probably have most of the same components. Only in your case the components are all integrated into a single book-sized portable unit.
Random Access Memory (RAM)There's too much "stuff" on your computer's hard disk to use it all at the same time. During the average session sitting at the computer, you'll probably use only a small amount of all that's available. The stuff you're working with at any given moment is stored in random access memory (often abbreviated RAM, and often called simply "memory"). The advantage using RAM to store whatever you're working on at the moment is that RAM is very fast. Much faster than any disk. For you, "fast" translates to less time waiting and more time being productive.
The Hard Disk
- Point: To point to an item means to move the mouse pointer so that it's touching the item.
- Click: Point to the item, then tap (press and release) the left mouse button.
- Double-click: Point to the item, and tap the left mouse button twice in rapid succession - click-click as fast as you can.
- Right-click: Point to the item, then tap the mouse button on the right.
- Drag: Point to an item, then hold down the left mouse button as you move the mouse. To drop the item, release the left mouse button.
- Right-drag: Point to an item, then hold down the right mouse button as you move the mouse. To drop the item, release the right mouse button.
The KeyboardLike the mouse, the keyboard is a means of interacting with your computer. You really only need to use the keyboard when you're typing text. Most of the keys on the keyboard are laid out like the keys on a typewriter. But there are some special keys like Esc (Escape), Ctrl (Control), and Alt (Alternate). There are also some keys across the top of the keyboard labeled F1, F2, F3, and so forth. Those are called the function keys, and the exact role they play depends on which program you happen to be using at the moment.
keyboards are created keeping in mind of QWERTY system , which was a popular system for type writers.
Combination Keystrokes (Shortcut keys)
- a printer that represents each character as a pattern of dots from a dot matrix
- A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like a typewriter. ...
- A type of printer that prints characters using an array of small wires that produce an array of dots when striking the paper
- A printer that forms characters or images using a matrix of pins that strike an inked ribbon.
- a printer that creates images through a series of small dots. Like other impact printers it impresses marks on the page, but unlike the line ...
- A very common type of printer that fires a row of tiny inked steel pins onto a piece of paper to produce readable text and graphic images.
- a printer in which each character is formed from a matrix of dots. They are normally impact systems, ie a wire is fired at a ribbon in order to leave an inked dot on the page, but thermal and electro-erosion systems are also used.
- A printer type that uses a pin-impact print head design to apply ink marks through a ribbon onto paper.
- Output device which prints characters by impacting the paper with clusters (matrix) of individual pins (dots).
- One of the earliest mass-market attempts at reliable, high-speed printing, dot matrix printers used a set of pins that could be fired rapidly at an inked ribbon to form characters on an underlying sheet of paper. While speedy, these printers suffered from relatively poor print quality. ...
- (DMP) - A type of printer that employs a movable printhead with pins, or wires, that shoot out and strike a ribbon. Each strike of a single pin creates a dot on the paper. Letters are formed as a pattern, or matrix, of dots. The most common are 9 or 24 pin printers.