Completed Module 2 — Operating Systems & Linux Ecosystem of NDG Linux Essentials by Cisco Networking Academy.
Software that runs on a computing device and manages hardware and software components to make a functional computing system.
OS acts as a bridge: Users ↓ Applications ↓ Operating System ← (Bridge) ↓ Hardware (CPU/RAM/Storage)
Two main jobs of OS:
- Multi-tasking — Shares processor so multiple tasks run simultaneously
- Standard Services — Handles requests from apps (like printing) to hardware
| Device | OS Type | Example |
|---|---|---|
| Desktop/Server | Complex | Windows, Linux |
| Firewall | Simple | pfSense |
| Mobile | Medium | Android (Linux-based) |
| Set-top Box | Simple | Custom Linux |
| OS | Code Base | Hardware | Admin Style |
|---|---|---|---|
| Windows | Proprietary | Any PC | GUI mostly |
| macOS | UNIX/BSD based | Apple only | GUI + CLI |
| Linux | Open Source | Any hardware | CLI preferred |
Key fact: Only Windows is NOT UNIX/Linux based. macOS and Linux both come from UNIX family!
| Feature | GUI | CLI |
|---|---|---|
| Resource usage | High | Low |
| Speed | Slower | Faster |
| Used by | Regular users | Admins/DevOps |
| Cloud servers | Rare | 90%+ |
Why DevOps Engineers prefer CLI:
- Less RAM and CPU usage on servers
- Faster to execute commands
- Scriptable and automatable
- More control over the system
- macOS is UNIX-based (BSD Unix)
- Linux is UNIX-inspired
- A UNIX admin can work on Linux
- A Linux admin can work on UNIX
- Skills are transferable! ✅
Microsoft's answer: PowerShell and WSL (Windows Subsystem for Linux) allow Windows admins to use Linux-style commands!
- OS is the bridge between hardware and software
- Multi-tasking = processor switching so fast it feels simultaneous
- Windows is proprietary — macOS and Linux are UNIX family
- CLI is preferred for server administration — less resources, more control
- UNIX and Linux skills are interchangeable
| Module | Topic | Status |
|---|---|---|
| 1 | Introduction to Linux | ✅ |
| 2 | Operating Systems & Linux Ecosystem | ✅ |
| 3 | Next Module | 🔜 |
| 4-18 | Upcoming | ⏳ |
- Platform: Cisco Networking Academy
- Course: NDG Linux Essentials
- Status: ✅ Module 2 Complete
Part of my 100 Days DevOps & Cloud Engineering Challenge Follow my journey: LinkedIn