If you’re just getting started with Linux server management, there’s one thing you must learn early: how to handle processes. Processes are basically the programs and tasks running on your server — some visible, many invisible. When something slows down, freezes, eats too much memory, or refuses to stop… knowing how to inspect and control processes becomes extremely important.

Don’t worry — you don’t need to be a guru to master this. I’ll walk you through each tool step by step, in the simplest way possible, like an older friend guiding you through your first Linux adventure.

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What Are Processes in Linux? (Very Simple Explanation)

Think of your Linux system like a kitchen:

• Each process is a chef working on a dish

• Some chefs (background processes) work quietly

• Some chefs (foreground processes) are loud and visible

• Too many chefs can make the kitchen chaotic

• And sometimes… you need to ask a chef to stop cooking

Tools like ps, top, htop, and kill help you “look into the kitchen” and keep things under control.

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⭐ 1. Seeing Running Processes with ps

The ps command is like a snapshot — it shows what's running right now.

Example: Show All Processes

ps aux

Explanation:

• a — show processes for all users

• u — show the user who owns each process

• x — include background processes too

This gives you a long, detailed list. If you're new, this list might look intimidating — that’s okay. What matters is you can now see what’s running.

Useful Tip: Search for a specific process:

ps aux | grep nginx

This helps you quickly find what you’re looking for.

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⭐ 2. Real-Time Monitoring with top

top is like a live dashboard. It updates every few seconds and shows CPU, memory usage, process IDs, and more.

Run it with:

top

Inside top, you’ll see:

• CPU usage

• Memory usage

• Load average

• All processes sorted by resource usage

Helpful Keys Inside top:

• P — sort by CPU usage

• M — sort by memory usage

• k — kill a process

• q — quit

This is perfect for spotting “greedy” processes that slow your server.

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⭐ 3. A Friendlier Version of top: htop

If top feels too old-school, htop will feel like a modern upgrade.

Install it:

sudo apt install htop   # Ubuntu/Debian
sudo yum install htop   # CentOS/RHEL

Run it:

htop

Why beginners love htop:

• Colorful

• Easier to read

• You can scroll

• Interactive controls

You can sort by memory, CPU, user, and more — all with arrow keys.

Most administrators use htop every day because it’s just more comfortable.

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⭐ 4. How to Kill a Process: Using kill

Sometimes, a process gets stuck…
Sometimes, it becomes a CPU monster…
Sometimes, an app refuses to close properly…

That’s when you need the kill command.

1. Find the Process ID (PID):

ps aux | grep appname

You’ll see a number — that’s the PID.

2. Stop the process gently:

kill PID_NUMBER

3. If it refuses to stop, use force:

kill -9 PID_NUMBER

Important: Use -9 only when absolutely necessary — it’s like pulling the plug.

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⭐ Real Life Example (Simple & Practical)

Let’s say your Node.js app froze.

Step 1 — Find it:

ps aux | grep node

You find PID 1834.

Step 2 — Try stopping it:

kill 1834

If it still doesn’t stop:

Step 3 — Force it:

kill -9 1834

Done — problem solved.

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⭐ When Should You Use Each Tool?