Hardware - Input, Output & Storage Devices
A computer is made up of several parts called hardware. These parts are essential for the computer to boot up. Hardware is something that we can touch for example mouse, keyboard, hard disk, monitor, CPU and other tangible peripherals. In this section we will see the most common parts & peripherals that you can use with a computer and categorize them into three groups, 1.Input Devices 2.Output Devices 3.Storage Devices.
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Let us first define what an input device is. An input device is a piece of hardware used to input information/data into the computer. Every time we scan a picture, type something in the keyboard, use the mouse to open up an Internet browser we are inputing something into the computer and the device we use is called an input device. It worths mentioning here that many people do get confuse with hard disks or USB flash memory as input device. USB flash memory is a storage device, yes we do plug it into the computer and can get files from the computer or put files into the computer. That is file handling. Thus a USB flash memory is a storage device. Now lets see few input devices.
- Mouse - no need to say anything for a mouse. I believe everyone on this planet know what a mouse is, especially the one used for the computer.
- Keyboard - the one used to type things on the computer.
- Joystick - mostly used for games especially airplanes and helicopters.
- Tracker ball - basically is an upside down mouse and is more precise than the common mouse.
- Track Point - its a mouse used on laptops and is between the keyboard keys saving space on Laptop's design.
- Graphics Tablet - used to draw designs on the computer similar to what you can draw with your pen in a piece of paper.
- Digital Camera - A Digital Camera is an input device when directly connected to the computer and used to take screenschots (images). For example you want to get a new ID card or this is your first time registering for College/University you need a picture, the guy at the registration office takes a picture of you that is saved directly on the software issuing your registration or ID card. This is digital camera used as an input device.
- Scanners - A scanner is a device used to convert any handwritten or printed paper and pictures into digital format in order to be processed by the computer. All the scanned documents are saved as an image. There are some special software and scanners we will see later in this article, that are cabable of reading characters printed on a piece of paper and actually create a "word" like file that will enable you to edit it as a normal Word Processing file instead of a picture.
- Hand Held Scanner - mostly used at supermarkets.
- Flatbed Scanner - mostly used for home and office to scan documents and pictures.
- Sheet-fed Scanner - occupies much less space compared to the above scanners.
- Optical Mark Recognition (OMR) - It captures human marks on a piece of paper such as surveys and tests.
- Optical Character Recognition (OCR) - It is the conversion of images of handwritten typed written or printed text onto digital format so that the computer can process it. Let's say that i have a written essay of 20 pages that i don't want to type in again. I can scan that essay using an OCR and get an editable word processing file.
- Magnetic Card Reader - It's used to read credit cards. That magnetic strip at the back of a credit card stores information such as: Name, Expiration Date, Type of Card, Laser four digits and maybe few more. The magnetic strip reader is used to read this information when swiping the card.
- Biometric Scanner - Yes this is an input device as well. Latest cutting edge technology. Basically a biometric scanner scans fingertips in order to compare it later on with a database and validate or reject your entry. Another type of biometric authentication is iris scanner. Iris is unique as our fingertip and can be used to identify a person.
- Sensors - another type of input device is sensors. Sensors are mostly used for data logging collecting data from the environment. There are quite few different types of sensors, just to mention few of them: light sensor, temperature sensor, senors to that measure air pollution, heat sensor, movement sensor and more.
- Audio Input Device
- Touch Tone Telephone.
- Voice Command
- Monitor - The most common output device when it comes to ICT. We would be blind with out a monitor. Nowadays we have different types of monitors CRT, TFT, LCD, Plasma... all of them can be used on a PC.
- Video Card / Display Card. Very well know as VGA. VGA stands for Video Graphics Array. Is the card that converts all the signals from the computer so we can see everything on our nice flat LCD monitor.
- Projector - Simply projects whats displayed on our monitor in a flat white surface.
- Printers. we have different types of printers. We will see the most common ones and list down their unique characteristics.
- Ink-jet Printer. It is commonly used for home its slower than laser printer but prints in better quality, especially when it comes to printing digital images/pictures.
- Laser Printer - Laser printer is becoming more popular over the days, particularly now that you can have color as well. The main characteristics of a laser printer is the amount of pages that can print in a single cartridge and how fast can do that.
- Plotter - Plotter is a big printer that was used for CAD (Computer Aided Design) applications, although now is replaced by common printers. Do you see those bid advertisements on the streets; are printed using plotters.
- Speakers - So you can listen to some music and relax after reading this long article.
- Hard Disk - Hard disk drive is one of the most common storage device. Although most people confuse hard disks or flash memory as input/output device this is not the case. Yes you can plug in your memory stick or external hard disk and transfer files or write file on your storage device but thats not input/output. Hard Disk Drive is used to store the operating system and data on a computer. We have internal and external hard disk drives. We need such storage devices to keep data even after the computer is switched off.
- Floppy Disk - Floppy Disk was one of the first portable storage devices but it has too many disadvantages. Just to mention few: Low capacity you could store only ~1.4MB of storage, you could loose your data easily because of dust or exposed to sun.
- Memory stick or Flash Memory - Most people calle them USB and that is wrong because USB is just the type of the port (connection) used to connect (plug) your memory stick on the computer. It's the most common external storage device based on EPROM (Erasable Programmable Read Only Memory) technology. Some of the basic advantages that make this storage device unique and high demanding is the small size thus portability, high capacity nowadays you have up to 128GB on a single usb flash memory (can you imagine in few years) and low price.
- RAID Controller - RAID stand for Redundunt Array of Inexpensive Drives. It uses common hard disks mostly on big servers. You can have for example RAID 5 which consists of 3 hard disks and using complex mathematic algorithms ensures that in case of one hard disk failure the other two will have all data stored on it. The capacity is usually the 2/3 of the total capacity of all three hard disks.
- CD (Compact Disk) - Compact Disk is a really cheap convenient way to share or transfer data. There is one major drawback, you can only write once.
- DVD Disc (Digital Versatile Disk) - It has the same size as CD's instead can hold up to 6 times more that a CD. It can hold up to 4.37GB and with the new technology, be able to write at both sides of the DVD you can have up to ~9GB.
- Zip Drive - Is similar to floppy disk instead can hold more data and is more reliable. There are zip drives with 100MB capacity and 250MB.
- Magnetic Tapes - Magnetic tapes look like and are similar to old radio cassettes. You cannot use them to load an operating system because a tape is way to slow but you can use it for backup purposes. It's cheap and can successfully store your backup data for long period of time if stored properly.