What Happens When a Computer is Turned On?
Difficulty: Beginner
Reading Time: 5 min read
Last Updated: June 30, 2025
What Happens When a Computer is Turned On?
💡 What really happens inside your computer the moment you press the power button?
It’s a process most of us take for granted — but behind the scenes, a fascinating chain of steps turns cold hardware into a living, working system.
From BIOS/UEFI checks and the mysterious POST beeps, to the MBR and bootloader, all the way through to Linux’s init (or systemd) launching daemons and graphical interfaces—this process is the foundation of everything we do in software engineering.
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Why does it matter?
Understanding the boot process isn’t just trivia — it’s the backbone of debugging, performance tuning, and even security hardening. Whether you’re a student exploring OS fundamentals or an engineer tackling low-level issues, knowing what happens at boot unlocks a whole new perspective on how systems really work.
Read the full article in my Notion blog here:
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The full article lives in my Notion blog here, which serves as the single hub for all my articles and ensures consistent formatting across platforms. You can read this article directly in the Notion link above. Feel free to share your thoughts or feedback in the site comments — or drop me a note on LinkedIn.
About the Author
Abdul-Hai Mohamed | Software Engineering Geek’s.
Writes in-depth articles about Software Engineering and architecture.
