What Makes Up A Computer
We all know about computers, I mean, unless you are reading this off a piece of paper you're using one right now. You may not, however, know what a computer is. We'll start with a definition of a computer.
A computer is a device that takes data as input and transforms it, using a set of instructions, into information. Basically, you enter something into the computer, like the pressing of a key on the keyboard, and the computer displays the letter on the screen. While this may seem pretty simple, the series of operations that occur to get that single letter on the screen is quite complicated. This brings us to hardware and software.
This is kind of self-explanatory. Hardware is all the parts of the computer you can see and touch. This includes your keyboard, mouse and speakers. It is these devices that are responsible for inputting data into the computer, as well as the output of information. For example, you may use a microphone to input your voice into the computer and it is hence an input device. You may also output(play) the recording through the speakers, hence it is an output device.
There are also storage devices, which you can use to save data on. For example, you can store(save) your data on the hard drive and access it at some later time. This is secondary storage. You may not necessarily save the recording, but for it to be inputted into the computer and processed, it needs to be held or stored somewhere. This memory is called RAM(random access memory) and is primary storage. Data in primary storage is lost when the computer is turned off(volatile) but the data in secondary storage is permanent(non-volatile), at least until you decide to delete it.
There is also memory referred to as ROM(read only memory). This memory is a type of primary storage and is used to store the operating system files, that is, files necessary for the proper start-up of the computer. While the data in ROM is, for the most part, permanent, it is referred to as primary memory because the state the data was actually in is lost if the computer is turned off.
The processor is what is considered to be the "brain" of the computer and is what follows the instructions that are software, to transform data into information. All processing done by the computer is actually done by the processor.
The software is a set of instructions a computer uses to process data into information. Data is all the raw facts and figures that by themselves have no meaning but can be given meaning and hence become information through processing by a program(software). This is similar to a random string of eight numbers on a piece of paper such as "25121986". You have no idea what these numbers are supposed to represent and therefore to you they hold no meaning. Through the processing of a piece of software that is typically referred to as a program, this data can be transformed to "Jake's date of birth is 26/12/1986", and hence is now information. The program attaches meaning to otherwise meaningless text.
The data for processing enters the computer through input devices. For instance, you could have entered these numbers through the keyboard. The monitor would be an output device to display these processed data(information), showing that the numbers represent Jake's DOB.
How Hardware And Software Make Computers Work
Firstly, before you can enter hit a button or use any device to input information, you must boot up the computer. On the ground level, this isn't as simple as hitting the power button, hitting this button only catalyses a series of processes with the end result being your computer turning on.
After you hit the button, this gives the signal computer to transfer the data that is in ROM to RAM, namely, the operating system data. After this data has been transferred to the RAM, the processor sets about processing the data and sends the processed data, now information, to the monitor, and this is the point you actually see the computer turning on. Note that all of these steps happen with milliseconds.
After the computer is fully booted(turned on), you can now input data for processing. Now we will examine the series of steps that occur for the computer to display the letter common "p" on the monitor display. On the outside, it may seem like simply pressing the letter "p" on the keyboard would give you the letter "p" displayed on the monitor, but the process is much more complicated that that. What we see as "p" on the keyboard is only a letter printed onto a button. To understand this process you must understand what is the binary system.
The Binary System
Computers function on what we refer to as the binary system. This means, the computer only represents data in one of two states, mainly off and on. "0" is used to represent the "off" state while "1" is used for the "on" state. We typically use the decimal system in everyday life where quantities are measured in multiples of 10( numbered from 0 to 9) and this is referred to as base 10. Similarly, the binary system measures quantities that are measured in multiples of 2(numbered 0 and 1) and this is called base 2.
How Hardware And Software Function Together
That binary code for the letter common"p" is actually "1110000". Note that the binary code for capital and common letters are different. So if you pressed the "p button", you would have entered the code "1110000" into the computer using the input device of the keyboard. This data would be saved in RAM with the instruction to display this data on the monitor. The processor would then processor this data, turning it to the letter "p" and the information would be sent to the monitor to be displayed. It would be up to you whether to save this information permanently on the hard drive.
This is the basis of how a computer functions. There are hardware and software. The software functions using the binary system which consists of 0's and 1's. Long strings of these zeros and ones are used to create software which, then, in turn, is used to give instructions to the hardware. Hardware can be used to put information into the computer in the form of data, the software processes this input and then the output is converted to a form humans can understand and made available back through hardware. This input, processing and output are the basic functions which make up a computer.