Computing Basics Flashcards
Hardware
Hardware refers to the physical components that are installed inside or connected to a computer system.
Hardware can’t work without Software.
Software
Software refers to instructions, or data, that are stored electronically either on a hard drive or on a special chip.
Input devices
An input device is any piece of hardware that takes information from outside the computer and transfers it inside where the computer hardware can use it.
Examples of input devices: Keyboard & Mouse
How a keyboard (input device) works
A keyboard takes user inputs and sends them as electrical signals to the internal computer hardware where they are processed. When a key on a keyboard is pressed, an internal chip called the scanning chip, identifies which key was pressed and then sends the appropriate code to the computer.
Two touchscreen technologies: Resistive & Capacitive
Resistive touchscreens use two flexible layers that are separated by a gap. Inside the gap is an electrical current. When the screen is tapped, the outer layer depresses and contacts the inner layer creating an electrical signal that identifies x,y-coordinates. The coordinates are then sent to the computer.
Capacitive touchscreens use a screen that is coated with a conductive material. An electrical current is then run through the material. When something conductive touches the screen, such as a finger, small sensors identify the touch and generate x,y-coordinates. Capacitive touchscreens are used on smartphones, tablets, and some laptops.
Note: Because they require a conductive touch, a non-conductive object, such as gloves or plastic, can’t be used to tap the screen. Resistive touchscreens are typically used for airport or library kiosks. Because they require only pressure, any rigid object can be used to tap the screen.
Processing Device
A processing device is any hardware component that can analyse and interpret input. The most common processing device is the central processing unit (CPU). The CPU is like the brains of the computer. It processes data according to a set of instructions or software.
E.G. When the “A” key on the keyboard is pressed, the keystroke information is sent to the CPU where it is processed based on the software that is currently running. If you were running word processing software, the letter “A” would appear at the cursor location in the open document. If you were running a game, it might make the character move to the left.
RAM - Processing device/Hardware Component
Random-access memory (RAM).
RAM is used to store processed information so it can be quickly accessed at a later time. E.G. if a CPU were to process data from a spreadsheet but still needed to access that data at a later time, the data could be stored in RAM for quick access. RAM is also used to store running software.
Storage Device
A storage device is any hardware component that stores data, either temporarily or permanently.
Note: When data is stored temporarily, short-term storage such as RAM is used. It’s important to know that RAM is considered volatile memory, that means it’s not persistent. For example, if the computer is turned off or loses power, all the data that was stored in RAM is lost. It’s gone forever.
Why use RAM if the data erases once turned off?
You use RAM because it’s extremely fast. Information can be accessed from RAM faster than any other type of storage hardware.
Short-term storage
Lost when the computer is shut down.
Long-term storage
Storage stored in the hardware, so when the computer turns off it is still saved once turned back on. Non-volitile memory.
Long-term storage Devices
Hard-disk drives store information on rotating disks called platters.
SSDs use memory chips that are a lot like RAM. However, the information stored on these chips is persistent.
Note: Hard disk drives and SSDs can store a lot of data and access it relatively fast but not nearly as fast as RAM. This is why you use both hard drives and RAM to store data.
Optical Storage Media
Optical-storage media can be read-only or writable. If a disk is read-only, the information it contains is fixed and can’t be modified or erased. It can only be viewed. An example, a read-only disk is a software CD-ROM or DVD-ROM. The ROM at the end stands for read-only memory.
Writable Disks
Writable disks can be modified. Disks that are writable have an R or an RW. For CD-R, DVD-RW, and BD-R, the R stands for recordable. Unlike their ROM counterparts, these types of disks can have information saved to them.
Flash Drive - Long term storage device
Flash drives are small, portable devices that use memory chips to store information. These memory chips are very similar to RAM chips. However, the information is persistent.
