The Role of Operating Systems

When we purchase a computer, it usually comes with an Operating System (OS), such as Windows, macOS, or Linux. If you’re reading this on a computer, it’s likely you’re using one of these systems.

An operating system is a substantial program that breathes life into a computer. It enables fundamental functions such as powering on, browsing the internet, playing music, and much more. Consequently, most users never encounter the state of a computer that lacks functionality.

Operating systems are bundled with smaller applications that provide specialized features. For instance, music playback is managed by media player software like iTunes or Windows Media Player, while web browsing is handled by programs like Chrome, Firefox, or Edge. These specialized applications operate within the broader framework of the OS, and users can install additional compatible software as needed.

Interacting with Computers: GUI vs. Text Commands

To access these features, we typically utilize a mouse or a Graphical User Interface (GUI), allowing us to command computers with simple clicks. For example, playing a song involves clicking on the application icon, selecting the song, and hitting play. Visual interactions tend to be more memorable for us.

However, there are alternative methods. Recall the cybersecurity expert I mentioned earlier; he utilized textual commands through programs like Terminal for macOS or CMD for Windows. This approach enables users to accomplish nearly everything without a mouse, a realm where many programmers thrive.

So, how do these applications know how to perform tasks intelligently? Let’s uncover the secret.

Decoding the Essence of Code

Every software application is governed by a set of instructions known as code. In essence, code directs a computer on what actions to perform, how to execute them, and when to do so.

Think of it like an instruction manual you receive when purchasing IKEA furniture. While the manual guides you through the assembly process, code must be even more detailed. Computers execute tasks with inhuman accuracy and endurance, but they require explicit instructions to function properly.

Users often have unpredictable behaviors, making it crucial for code to anticipate various scenarios. This is where the role of programmers comes into play; they create solutions to potential challenges. If not, the system may fail to operate as intended.

As Rachel Potvin, a Google engineer, mentioned in a conference, “the software required for Google’s Internet services—ranging from Search to Gmail to Maps—comprises approximately 2 billion lines of code.”

Ultimately, the true magic lies within us, as humans collectively strive to craft intricate and efficient software that enhances our lives. Behind every seamless application or system lies a dedicated team of developers responsible for writing millions of lines of code, which serve as the foundation of functionality.

Example of PHP Code

Here’s a simple example of PHP code that requests a user’s full name and then displays a personalized greeting:

<?php

$name = readline("Please enter your fullname: ");

echo "Welcome ".$name."n";

When executed, this code prompts the user:

Please enter your fullname: Sayem Shahid

Welcome Sayem Shahid

To illustrate this process, I’ve created a brief YouTube video demonstrating the code in action.