Category Everyday Science

A Pixel is a tiny dot of color, which, together with millions of other dots, makes up a picture on a computer or television screen. It is short for “picture element”. A pixel is the smallest unit of a digital image or graphic that can be displayed and represented on a digital display device.

A pixel is the basic logical unit in digital graphics. Pixels are combined to form a complete image, video, text or any visible thing on a computer display. A pixel is also known as a picture element.

A pixel is represented by a dot or square on a computer monitor display screen. Pixels are the basic building blocks of a digital image or display and are created using geometric coordinates. Depending on the graphics card and display monitor, the quantity, size and color combination of pixels varies and is measured in terms of the display resolution.

For example, a computer with a display resolution of 1280 x 768 will produce a maximum of 98,3040 pixels on a display screen. Each pixel has a unique logical address, a size of eight bits or more and, in most high-end display devices, the ability to project millions of different colors.

The pixel resolution spread also determines the quality of display; more pixels per inch of monitor screen yields better image results.

Inside the processing unit of a computer are collections of integrated circuits (microchips) and other components, usually positioned on circuit boards. There are also slots for floppy disks and CDs to be inserted, a “hard disk” on which data is stored, and perhaps devices such as fans to keep the components cool. Portable computers also have space for a battery, which can be recharged.

It is imperative to understand the name and function of each component in a computer in order to understand how it functions as a whole. Attempt to always remember that a computer is based off the human body and functions in the same way. You cannot expect to understand the human body without first understanding its organs and their functions. A computer is composed of components in the same way that the body is composed of organs that together work to make the body or computer function. A basic computer has at least 8 basic components which include a computer case or tower, motherboard, Central Processing Unit (CPU), Power Supply Unit (PSU), Random Access Memory (RAM), hard drive (HDD), Graphic Processing Unit (GPU) and some type of optical drive which would be your CD/DVD drive. These 7 components are the backbone of every healthy, functioning computer.

Motherboards

Motherboards often referred to as a logic board, main board or “mobo” for short, are the “back-bone” of the computer. Its purpose is to connect all the parts of the computer together and make everything centralized using its printed circuit board. The central processing unit, hard drives, memory, graphic processing unit, printers, and other ports all connect to the computer directly or via special cables that attach on to the motherboard. When you plug in a USB or thumb drive to a computer you are actually plugging it directly into the computer!

Power Supply

True to its name, the power supply powers all other components of the machine. It usually plugs into the motherboard to power the other parts. The power supply connects to either an internal battery (on a laptop) or a plug for an outlet (on a desktop).

Central Processing Unit (CPU)

A CPU, sometimes referred to as a computer’s brain, is the workhorse of the machine. It performs the calculations needed by a system, and can vary in speed. The work that a CPU does generates heat, which is why your computer has a fan inside. A more powerful CPU is necessary for intense computer work like editing high-definition video or programming complex software.

Random-access Memory (RAM)

RAM is temporary memory. Whenever you open up a Microsoft Word window, your computer places it in RAM, and when you close the window, that RAM is freed. Since RAM is volatile, its contents are lost if the machine loses power. This is why you lose a Word document when the power goes out if you didn’t save it.

Hard Disk Drive / Solid State Drive

Since RAM is temporary, your computer needs a place to store data permanently. That’s where the hard drive comes in. The traditional hard drive consists of several spinning platters with an arm that physically writes data to the disk. However, these drives are slow and are starting to be replaced by the faster solid-state drives.

Video Card

A video card is a dedicated unit for handling the output of images to a display. Video cards have their own dedicated RAM for performing these functions. A high-end video card is required to process extremely intense visual functions, such as computer drafting by engineers. Like many components, many types of video cards are available with varying power and prices.

Optical Drives

Though less common than they used to be, many machines still have an optical drive for reading CDs and DVDs. These can be used to listen to music or watch movies, place information onto a blank disc, or install software from a disc. Since most software nowadays is installed from the internet instead of using discs, these aren’t as important as they once were, especially on laptops.

Input and Output Devices

Depending on your particular computer, you can connect a variety of devices to send information into it or out of it. Common input devices include mice (touchpads on laptops), keyboards, and webcams, while output devices consist of monitors, printers, and speakers. Removable media such as flash drives and SD cards can also be used to transfer data between computers.

An optical mouse is technologically much more advanced than a mechanical mouse. Unlike the latter, an optical mouse is completely electronic and therefore has no moving parts. It consists of an LED (that generates the signature red light), a light-detector chip, a switch mechanism and a few other simple components. Some mice have another LED that lights up a plastic strip installed at the back of the mouse as an indication of the mouse’s operation.

The LED installed at the bottom of the mouse emits a bright light in the downward direction. Since a mouse is usually used on plain surfaces, the light bounces back from the surface and enters a photocell that’s also mounted on the bottom, almost next to the LED. This photocell has a frontal lens that magnifies any light reaching it. As you move the mouse around, the pattern of the reflected beam changes; this is then used by the light-detector chip to figure out how and in which direction you’re moving the mouse.

Some optical mice have two LEDs. The first one shines light down onto the desk. The light from that is picked up by the photocell. The second LED lights up a red plastic strip along the back of the mouse so you can see it’s working. Most optical mice also have a wheel at the front so you can scroll pages on-screen much faster. You can click the wheel too, so it functions like the third (center) button on a conventional ball mouse.

Optical mice are much lighter and faster than mechanical ones, and have therefore gained enormous popularity all over the world. With improvements in technology, newer and even more advanced mice – that address issues like ergonomics and the health of the user – are taking center stage. The choice of the right variant rests with the user, but one thing remains universally true – computers and mice shall always remain inseparable.