Simply put: a system is a combination of parts that work together to achieve a goal. Based on this definition, we can easily see how a computer fits the description of what a system is. All computers have a way to accept user input and receive instructions from users, a way of delivering data back to the user, a central processing unit, basic hardware, and software.
After a computer receives data from an input device, the data must be processed before it is sent to an output device such as a monitor. In a computer, a data processing device is any device that is responsible for the storage and retrieval of data. Listed below are the data processing devices located in a computer.
Watch: Data Processing Components
Data processing components are responsible for collecting, structuring, normalizing, and analyzing data. When a computer receives data from an input device, say you type the letter B on your keyboard, something must process an incoming data before it can display the letter on your monitor. This is, of course, a simple example. There are different data processing components that process more complicated digital information, such as images, videos, sounds, and more.
The central processing unit, or CPU, is the core processing component of a computer. The CPU is the brain of the device because it carries out commands sent to it by other components and returns results to be acted upon. The graphics processing unit, or GPU, processes and generates images for display on the monitor. A more common name for the GPU is a video card.
The motherboard is the main circuit board on the computer to which many other components are connected, such as the CPU, memory sticks, hard drive, and video and sound cards. A network interface card, or NIC, also called an ethernet card, allows the computer to connect to a network, such as the internet, and gives the computer access to servers and printers to share resources.
A sound card or audio card is responsible for producing sound through speakers or headphones. Sound cards aren't essential for computers to operate, but they are necessary to be able to hear audio in multimedia files like games or movies.
In a computer, data storage is handled by several components. Generally, a data storage component is any hardware that can store information temporarily or permanently. Data storage devices are classified as either primary storage or secondary storage. Primary storage refers to internal storage, such as random access memory (RAM). Secondary storage is not readily accessible by the computer and can be internal or external, such as a hard drive or flash drive. Listed below are the data storage components located in a computer.
Watch: Data Storage Components
There are many different hardware components that store data, either inside the computer itself or in an external or peripheral device. Devices that store data internally are called primary storage devices, and devices that store data externally are called secondary storage devices. Let's begin with the primary storage devices.
Hard drives exist in two different technologies-- a hard disk and a solid-state drive. A hard disk consist of spinning magnetic disks and a solid-state drive uses flash memory. Solid-state drives are faster and lighter, which makes them desirable to users. But they also tend to be more expensive.
Both hard disks and solid-state drives provide long-term storage for computing devices. Memory is stored in the hard drive when the computer is turned off, and when you turn your computer back on, data is retrieved from the hard drive.
Flash drives are small, portable storage devices that connect to the universal serial bus, or USB, connector. USB ports are standard on all personal computers today. So users can store files, such as documents, photos, movies, et cetera, on flash drives and easily transfer files from one device to another.
Random access memory, or RAM, can quickly access and transfer data from the hard disk. When you run a program on your computer, it is loaded into RAM for processing. Generally, the more programs you run at once, the more RAM it uses. And will likely slow down or even freeze if you try to do too much at once. An important difference between RAM storage and hard drive storage is that anything stored in RAM is lost when the devices turn off.
An optical disk is an electronic data storage medium that can be written to and read using a low-powered laser beam. Data is stored as micron-wide dots of light and dark. A laser reads the dots, and the data is converted to an electrical signal, and finally to audio or visual output. There has been a constant succession of optical disk formats, First in CD formats, followed by a number of DVD formats.
All computers accept input from the keyboard or mouse (or other designated input device), process it, and output it to a monitor (or other designated output device). An input device is any hardware component that sends data into a computer. An output device is any hardware component that sends data out of a computer.
Below are the common input and output devices utilized by most computer systems.
All personal computers need components that allow the user to input data. Keyboards help the user enter text or numbers as input for documents or files. Keyboards are available in different sizes. Some keyboards are designed for ergonomics, while others are designed to be small.
A pointing device is an input device that moves an on-screen pointer and gives users the ability to click to initialize applications, or to open files. The most common type of pointing device is a mouse. Users move the mouse across a flat surface and press a button to click. Another type of pointing device is a touchpad. A touchpad is a touch-sensitive pad that is built into a notebook computer and is designed to behave like a mouse.
Scanners allow users to input documents into a computer, either as images or as text. Most scanners have flat surfaces for users to place documents to be scanned on. However, some scanners feed documents one page at a time. Most scanners utilize the USB interface.
A digital camera is a device that captures a picture and converts it into digital information. Most digital cameras provide a local storage option until the picture can be transferred to a computer. Typically, a digital camera connects to a computer using the USB interface.
A monitor is a device used to display video, images, or text. With a laptop computer, the monitor is built in, and with a desktop computer, the monitor comes as a separate component connected to the system unit via cable (typically VGA). Most monitors are used only for output, but some, such as touchscreen monitors, can be used for both input and output.
A printer is an output device that generates a hard copy of work created on a computer. All printers do the same basic thing: they print an image on a page. A printer's quality, cost, speed, and overall ability vary.
Some devices can be both input and output devices if they are allowed to get information into the computing system, and also send information back out of the system. For example, a printer that has a scanner is both an input and an output device. A touchscreen is another example. The output is the monitor display, and the input is the touch interactions to click, zoom in, and zoom out.
Source: Derived from Chapters 2 and 3 of “Information Systems for Business and Beyond” by David T. Bourgeois. Some sections removed for brevity. https://www.saylor.org/site/textbooks/Information%20Systems%20for%20Business%20and%20Beyond/Textbook.html