How Computers Work : A Step-by-Step Guide for Beginners

You can’t escape computers these days. They are found everywhere from the phones we carry around with us to the laptops sitting on our desks. However, have you ever thought about how these devices actually work?

This guide will take you through a thorough step-by-step analysis of what computers really do in the easiest way possible so that anyone who is just starting out can grasp the concepts.

A Computer Defined

At its most basic level, a computer is an electronic device designed to process input and generate output. Processing consists of receiving input, performing some computation on it (e.g., arithmetic), and finally presenting the user with some valuable output.

There are numerous varieties:

• Desktops: Traditional computers that are typically used for work and gaming
• Laptops: Portables designed for day-to-day activities
• Servers: Very powerful machines designed to manage websites or large databases
• Smartphones and tablets: Pocket-sized computers

The Fundamental Components of a Computer

Every computer has a few fundamental components which work together to create a functional unit. These include:

• CPU (Central Processing Unit): Also known as "the brain," the CPU carries out all of the processing involved in executing computer programs.
• RAM (Random Access Memory): RAM is temporary memory that is utilized by the CPU while the system is operating.
• Storage (HDD and SSD): Where the data and software of the computer and OS are kept permanently.
• Motherboard: The central component of a PC, the motherboard interconnects all of the other components of the system.
• Input Devices: Devices that allow users to provide information to their computer; examples include a keyboard and a mouse.
• Output Devices: Devices that allow users to visualize the result; examples include a monitor and a printer.
• Power Supply: Supplies power to all elements of a PC.

Data Flow in Computers

Computers utilize a straightforward operational method.

Input → Processing → Output Process

• Input: Your keyboard/mouse/microphone provides you with input.
• Processing: The Central Processing Unit processes your input with the assistance of software programs.
• Output: Your results are shown on monitors/speakers/printers, etc.

Binary code represents everything within a computer using just two symbols (0 and 1), which translates into electrical signals that the computer utilizes.

The CPU

Your CPU is your computer's "brain." It is composed of two principal components:

1. The ALU (Arithmetic Logic Unit): Executes calculations and logical processes. 

2. Control Unit: Regulates the transfer of information and commands within a computer.

The CPU uses the "Fetch, Decode, Execute" Instruction cycle to function.

Fetch: Collects the command from the computer's memory.

Decode: Identifies the command's purpose.

Execute: Completes the relevant task, whether it is to add two numbers together or to output a particular message on the screen.

Memory and Storage Explained:

1. RAM: Temporary storage for the running software. Fast, but memory is erased once the computer turns off.

2. ROM: Long-Term storage for the computer's essential instructions to start up the system.

3. Cache Memory: Fast access memory within the CPU for fast access to data.

4. HDD (Hard Disk Drive)/SSD (Solid State Drive): The location where you save your files and storage for your programs and operating system.

Instructions to Computer via Software and Networking

The Software is the vehicle that provides instruction to the Hardware of the Computer.

The Operating System, (i.e. Windows, Mac, Linux), maintains the functioning of both the hardware and the Software.

Applications are the many pieces of software that "perform," for instance. Microsoft Word, Adobe PhotoShop and Internet Browsers.

If there were no software designed to run on Hardware, hardware alone would have little or no benefit.

The Cycle of Input to Output

Let's observe this cycle in action. You type a document into Word (your input). The CPU receives your generated keystrokes and holds (processes) the document in RAM. The output is that you see the typed document on your monitor and saved on your storage device.

Networking

Computers use a means of communicating through a "network."

Each computer is assigned an Internet Protocol Address (IP) as the location of that computer, essentially its "home."

When data moves through the Internet, it is transferred in small packets.

The Internet is comprised of millions and millions of computers around the globe, all connected to each other.

A real life example of how a computer or search engine works:

You want to search the web for information on "how computers work."

Your input to the search engine was the "Search" button (your typed query). Your query goes from your browser to a server where it is processed, and results returned to you are your output. Your output will display on your monitor a list of all relevant web sites.

The Working of Computers

At first glance, learning about how a computer works can be overwhelming. Essentially, the operation of a computer is based on three basic functions: input, processing and output. The various parts of your computer including the CPU, RAM, storage, software and all of the other components work in unison to provide access to digital information.