1. Computer Applications Unit A
Hardware

2. Hardware-What is it?
Definition-The mechanical, magnetic, electronic, and electrical devices comprising a computer system.
Hardware is the physical components of a computer, therefore you can physically touch it, unlike software.

3. Here are the Main Components of a computer.
Computer Tower
Monitor
Keyboard and Mouse
The printer represents external devices which we will also be talking about.

4. The Tower

5. The Motherboard The motherboard is the main printed circuit board.
Many crucial electronic components such as CPU and RAM are housed here.
The motherboard also contains slots which allows for expansions such as video cards, sound cards, network cards, etc.
Contains basic instructions for the computer, known as BIOS.

6. The CPU Central Processing Unit Known as the brain of the computer.
The device carries out many of the arithmetic, logical, and input/output operations of the system.
There is usually a large fan placed directly over the CPU to keep the temperature cool.

7. Memory (RAM) RAM stands for Random Access Memory.
Used to store temporary instructions for the computer.
Allows for high speed transfer of information.
If the power is shut off from the computer, information in RAM is lost.

8. Power Supply Unit What supplies the energy to the computer.
Larger power supplies are needed for computers that require more energy. (I.e. computers with powerful graphics cards draw a lot of power and usually require greater than a 500W PSU)
Uses a fan in order to vent heat generated away from the temperature sensitive computer.

9. Hard Drive (HDD)
Used as a storage medium which contains the Operating System.
Typically is a metal disc that is coated with a magnetic material for storing data.
Data is not stored front to back, but is random access.
This means data can be retrieved in any order and not just sequentially.
However, this can lead to disk rot, as a program could be located anywhere throughout the hard drive, increasing retrieval times.
There is an alternative in Solid State Drives, which do not use the metal disc.
Due to no spinning disks or magnetic heads that read/write data, the SSD is more durable and has quicker access times.
However, the cost of SSDs is still 7-8 times higher than that of traditional hard drives.

10. Media Drives
Media Drives are used a form of allowing the computer to read extra data from an external source.
Examples are CD-ROM, DVD-ROM, DVD-RW, and even Blu-Ray combo drives.
ROM stands for Read Only Memory.
This means that the data, once written, can only be accessed and cannot be changed.
Many forms of disc media are being replaced by flash memory (such as USB sticks) due to greater storage and faster transfer speeds.
Digital storage and streaming are also decreasing the need for a physical drive to read media as many applications are now being stored in the cloud.
The “Cloud” will be elaborated on in a later chapter.

11. Video Cards and Other Internal Cards
Often added to increase the performance of or to give the computer access to something that is not included with the motherboard.
Video cards are typically added to increase visual performances.
Used largely in gaming, visual rendering such as CAD or AutoDesk, and more.
Sound cards are often added to give an increased sound performance.
Sound and video cards are often integrated into the motherboard, but usually are not designed for high performance tasks.
Network cards are added to give a computer access to either a wired or wireless network.

12. Input Devices
Input Devices are any devices that give user input to the computer.
Best examples are the Keyboard and Mouse.
The Keyboard usually inputs characters to the computer, providing input.
Characters are both letters and numbers.
The Mouse is an input device that interacts with the user’s monitor to give a visual direction of the user wants to be “clicked”.
Other input devices include graphic tablets, MOBIs, and even Webcams.

13. Output Devices
Both the monitor and the printer are examples of what are known as output devices.
Output devices are devices which give information back to the user.
The monitor displays visual information that the user can view and read.
The printer displays information by printing it onto a sheet of paper.
Technically all output devices “print” to an external device and allow the user to read it.
A projector is an example of another output device.

14. The Future of Hardware?
As physical components get smaller, faster, and able to handle greater amounts of data, the question is how much longer before we reach the physical limit of the hardware?
The advent of the “Computing Cloud” has made the need for physical hard drives to increase in size useless.
Perhaps in the future, we will have a computer that requires very little components. Only time will tell.