Monitors is the most frequently used output device. Also called display screens, monitors display visual images of text and graphics. Output is often referred to as soft copy. Monitors vary in size, shape and price. Features. 
Features
The most common feature of a monitor is its clarity. Clarity refers to the quality and linearity of the images displayed. It is one of the many features of a monitor, including resolution, dot pitch, contrast ratio, size and aspect ratio.
- Resolution is one of the most important feature. Images are created on the monitor from a series of dots or pixels (elements of the picture). The resolution of these dots or pixels is expressed as a matrix. For example, many monitors today have 1,920 pixel columns and 1,080 pixel rows for a total of 2,073,600 pixels. The higher the resolution of the monitor (the more pixels), the clearer the resulting image. Refer for the most common monitor resolutions
- Dot (pixel) pitch is the distance between each pixel. Most new monitors have a dot pitch of 0.30 mm (30/100th of a millimeter) or less. The lower the dot pitch (the smaller the distance between the pixels) the clearer the resulting images.
- The contrast ratio indicates the monitor's ability to display images. It compares the intensity of light from the brightest white to the darkest black. The higher the ratio, the better the monitor. Good monitors usually have a contrast ratio between 500: 1 and 2000: 1.
- Dimension, or active display area, is measured by the oblique length of the monitor's viewing area. Common sizes are 15, 17, 19, 21, and 24 inches.
- The aspect ratio indicates the proportional relationship between the width and height of the display. Usually, this relationship is represented by two digit semicolons (). Many older, square-shaped monitors have an aspect ratio of 4: 3. Almost all newer monitors have an aspect ratio of 16: 9 designed to display wide-screen content. Another important monitor feature is the ability to accept input of touch or gestures such as finger movements such as swipe, slide and tweak. While most older monitors do not support touch input, it is becoming a standard feature of more new monitors.
Flat-panel monitors
Flat-panel monitors are one of the most widely used monitors today. Compared to other types, they are thinner, more portable and require less power to operate.
Most all flat-panel displays are side-illuminated, meaning that a common source of light is spread over all the pixels on the screen. There are three basic types of flat-panel monitors: LCD, LED, and OLED.
- LCD (liquid crystal display) is more widely used for older types of monitors and is usually less expensive.
- LED (light-emitting diode) monitors use the same technology as the more advanced backlighting technology. They produce better quality images, are thinner and are more environmentally friendly as they require less power and fewer toxic chemicals to produce. Most new monitors have LEDs.
- OLED (Organic Light - Emitting Diode) monitors replace the backlighting technology of LED monitors. It contains a thin biological compound that produces light. By removing the backlight, OLED monitors can become thinner and with better power efficiency and contrast ratio.
Curved monitors
One of the most recent inventions is the curved monitor. It uses the same technology as flat-panel monitors, only its screen is concave which gives a better viewing angle near the edge of the screen. Curved monitors are widely used in high-end televisions and for gamers looking for a largely confusing experience. Curved monitors smartphones and Wearables have only recently begun to appear in computers. For smartphones, curved monitors can wrap the screen around the phone for optional display and button options. For a smartwatch, a large display curved screen that outlines the shape of your wrist.
E-book readers
E-book readers E-books (electronic books) are electronic formats of traditional printed books. These books are available from many public and private libraries, bookstore websites, and numerous sources on the cloud. E-book readers (e-readers) are mobile devices dedicated to storing e-books and other electronic media, including electronic newspapers and magazines. The displays in e-book readers are usually 6 inches and use a technology called e-ink. E-Ink produces images that produce the same light as regular paper and make the display easier to read. Two prominent e-book readers are Amazon's Kindle and Barnes & Noble's Nook Simple Touch.
Tablets can also display e-books. They are bigger, heavier and more expensive than e-book readers. They are also very flexible. E-books is one of their many applications. LCD displays not used in dedicated e-book readers are used in these tablets which give crisp, colorful images. However, due to their reflective nature, they are difficult to read in light. The two most popular traditional tablets are Apple's iPad and Samsung's Galaxy Tab.
Other monitors
There are many other types of monitors. Some are used for more specialized applications, such as presentations and television viewing.
- Digital or interactive whiteboards are specialized devices that have large displays connected to a computer or projector. The computer's desktop is displayed on a digital whiteboard and is controlled using a special pen, finger or any other device. Digital whiteboards are widely used in classrooms and corporate boardrooms.
- Ultra - High - Definition Television (UHDTV) offers a clearer and more detailed wide - screen picture than the usual HDTV.
