Computer Hardware

All you need to know about computers

Introduction

Hello and i am going to tell you all about computers. Now for this poster I am going to tell you about hardware's, Optical drive, Input and Output devices, Moniters and Touch Screens.

Hard Drive

A hard drive is what you use to store data and folders that you need for stuff. As you can see by the picture it may look  samll but it can hold over 100 GB. Hard drives are very fast so you can access files easily and fastly. The data is stored instantly, even if you turn it off. that is all you need to know about Hard Drives. 

Optical Drive

Optical Drive reads data on Optical disks. Coomon ones are CDs, DVDs, Blu-ray drives etc. These disks are mude up of millions and millions of dips. Optical drives have lasers which detects these dips as ones and zeros, which the computer can understand. This laser used for this data is much more powerful than the laser that reads the dat asit burns the dips. However they are slower than Hard drives, which can store data magneticlally. However, because optical media is inexpensive and removable, it is the most common format used for distributing computer software.

Input Devices

An Input device is any device that plugs into your computer or laptop. There are dozens of possible input devices, but the two most common ones are a keyboard and mouse. Every key you press on the keyboard and every movement or click you make with the mouse sends a specific input signal to the computer. These commands allow you to open programs, type messages, drag objects, and perform many other functions on your computer. Input devices are vital. Imagine using a computer without having a mouse or a keyboard. While most computers come with a keyboard and mouse, other input devices may also be used to send information to the computer. Some examples include joysticks, MIDI keyboards, microphones, scanners, digital cameras, webcams and card readers. Input devices are very important for plugging in equipment you need for a computer or laptop.

Output Devices

Any device that outputs information from a computer is called an output device. Most information from a computer is output in either a visual or auditory format, the most common output devices are the monitor and speakers. These two devices provide instant feedback to the user's input, such as displaying characters as they are typed or playing a song selected from a playlist. There are many other devices, not just monitors or speakers. For example, headphones, printers, projectors, lighting control systems and audio recording devices. A computer without a output device is pretty useless, since the output is what we interact with. So you see an output device is just as important as an input device.


Moniters

A monitor is basically your computer screen. The monitor displays the computer's user interface and open programs, allowing the user to interact with the computer, using the keyboard and mouse. Monitors often look similar to televisions. The main difference between a monitor and a television is that a monitor does not have a television tuner to change channels. Monitors often have higher display resolution than televisions. A high display resolution makes it easier to see smaller letters and fine graphics.

There are three types of computer displays:

  • The CRT monitor. These are heavy, use a lot of desk space and electricity. It is the oldest technology used by monitors and is based on the cathode ray tube technology that was developed for television. Monitors are made with better parts which give a much higher display resolution and picture sharpness than a television. This type of monitor is no longer popular.

A LCD Flat panel. Much thinner and lighter than monitors with a cathode ray tube.
  • The LCD monitor. Often called a Flat panel display. It is a newer technology than CRT. LCD monitors use much less desk space, are lightweight and use less electricity than CRT. This type of screen has been used for many years in the screens of laptop and notebook computers. It is also used for screens in every mobile phone, and many handheld technologies. It can produce a very high quality and stable display of graphics and text.
  • In the early 21st century the price of video projectors has fallen and they are now used in many places to produce very large images. These use a range of different technologies to make the image including LCD - Liquid crystal display and DLP - digital light processing which uses very small mirrors to direct the light.




Touch Screens

A Touch Screen is

A type of display screen that has a touch-sensitive transparent panel covering the screen. Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen.

Although touch screens provide a natural interface for computer novices, they are unsatisfactory for most applications because the finger is such a relatively large object. It is impossible to point accurately to small areas of the screen. There are three types of touch screen technology:


  • Resistive: A resistive touch screen panel is coated with a thin metallic electrically conductive and resistive layer that causes a change in the electrical current which is registered as a touch event and sent to the controller for processing. Resistive touch screen panels are generally more affordable but offer only 75% clarity and the layer can be damaged by sharp objects. Resistive touch screen panels are not affected by outside elements such as dust or water.



  • Surface wave: Surface wave technology uses ultrasonic waves that pass over the touch screen panel. When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves registers the position of the touch event and sends this information to the controller for processing. Surface wave touch screen panels are the most advanced of the three types, but they can be damaged by outside elements.



  • Capacitive:: A capacitive touch screen panel is coated with a material that stores electrical charges. When the panel is touched, a small amount of charge is drawn to the point of contact. Circuits located at each corner of the panel measure the charge and send the information to the controller for processing. Capacitive touch screen panels must be touched with a finger unlike resistive and surface wave panels that can use fingers and stylus. Capacitive touch screens are not affected by outside elements and have high clarity.