With fast and changing technology in this 21st centaury, presentation and interaction between individuals and groups has evolved from basically handing out notes to graphical presentation i.e. interactive whiteboards , with uses of graphics, sounds and videos to make the presentation more interesting and less time consuming to prepare. An interactive whiteboard is a touch-sensitive projection screen that allows you to control a computer directly by touching the board rather than using a keyboard or mouse.

An interactive whiteboard needs a multimedia projector and a computer to display. With the connection of the projector to either a pc or laptop, the displays are then seen on the interactive whiteboard which acts as a display screen. There are several different types of interactive boards but the two most popular are: pen (works on electromagnetic technology) and analog resistive (finger).

Computer interactions are usually carried out on the help of mouse, but with an interactive whiteboard you can touch the buttons and carry out functions without having to click on the mouse. The interaction on a white board is done with either the finger itself or a special pen. Interaction on a whiteboard is similar to the use of mouse where here the pen or finger acts as the mouse and the cursor follows with the pens or fingers movement and to perform a function you simply double tab on the desired section of the screen.

The finger touch sensitive whiteboards are ideal for use in the different sectors of buth education and business training environments which includes schools and colleges. The corporate and training organisations can choose the best type of digital whiteboard according to their needs. Medical environments usually use the finger touch boards such as dragging pictures or having other functions. Whereas Business environments tend to use finger touch boards for report presentations.

Interactive whiteboards are connected to the computer through either USB or a wireless network. The software device driver is usually loaded to the computer and then the board can be used with the pc and projector. Whiteboards come with built in OCR (optical character recognition) which means the characters you write on the screen can be recognised by the computer and be run as commands.

A CRT projector uses a small, high brightness CRT (picture tube) as the image generating element. The image is then focused and enlarged onto a screen using a lens in front of them. The earlier CRT projectors used to be monochrome, nowadays in a modern CRT projector you can find 3 different colour tubes blue, red and green along with their own lens to display the image or data on a screen.

The red, blue and green portions of the incoming video signal are processed and sent to the respective CRTs whose images are focused by their lenses to achieve the overall picture on the screen. These types of projectors are ideal for use in homes; businesses; educational centres etc. with proper tube size, video processing and lens combination, and an lcd projector can produce excellent displays.

The most common resolutions for a CRT projector are 800 × 600 and 1024×768 pixels. The various advantages and disadvantages of this type of projectors are:
Advantages: Can achieve very good resolution, brightness and picture size. Has a long tube life or projection life (22,000 hours).

Disadvantages: It’s large in size, bulky, non portable, more expensive than other projectors and has low maximum brightness level.

An LCD (Liquid Crystal Display) projector is a type of video projector used for displaying video, image or computer data on a screen or other flat screen surface. LCD projectors contain three separate LCD glass panels, one for red, green, and blue components of the image signal being transferred to the projector. As the light passes through the LCD panels, individual pixels can be opened to allow light to pass or closed to block the light. This activity modulates the light and produces the image that is projected onto the screen . Some advantages and disadvantages of this type of projectors are:

Advantages – generally more light efficient, lcd projectors tend to produce more saturated colours.

Disadvantages - Generally more bulky, as there are more internal components. If it fails it’s very expensive to replace.

LCD projectors are now becoming the defacto standard type of projector on the market today.

A projector is a device that integrates a light source, optics systems, electronics and display(s) to project an image from a computer or video device onto a wall or screen to increase the display size for long distance viewing. These devices attach to a computer or video device as you would connect a monitor or television. It is an ideal device for any individual or a business as it serves various different purposes for displaying information.

The display of a projector differs on various aspects of the projector such as resolution, brightness, noise level, display size, contrast, and aspect ratio. Projectors are categorised into two groups: Video projectors and Transparency projectors.

The size and quality the video projectors display varies from one projector to another based on its resolution, brightness and other specifications. The common display resolution sizes that most of today’s projectors support are:

SVGA(800 × 600 pixels)
XGA(1024×768 pixels)
720p(1280 × 720 pixels)
1080p(1920 × 1080 pixels)

The pixel is a basic unit of composition of an image on any display screen TV screen, computer or any display screen. It is a single, addressable point on a graphic screen. Screens are rated by their horizontal to vertical pixels like 1024×768 pixels, means a display screen has 1024 pixels horizontally and 768 pixels vertically.

The more pixels the screen contains the more the displayed data can be close to the original or more realistic. For coloured displays the pixels red, blue and green sub-pixels are each energized to a particular intensity, and the combination of the three colour intensities creates the perceived colour to the eye.

The cost of an LCD projector varies mostly on the basis of resolution but there are other characteristics that make up the difference such as: light output, acoustic noise output and contrast