When you open a Linux terminal for the first time, you might see something like:

/home/username $

or sometimes:

~ $

At first, this can be confusing.

👉 What is /?
👉 What does ~ mean?
👉 Who is username?
👉 And what is this “root” everyone talks about?

Let’s understand all of this step by step in a simple way.

🌳 Linux Does Not Use C:, D: Drives

In Windows, files are organized into drives like C:, D:.

Linux works differently.

👉 It uses a single filesystem structure that starts from:

/ — Root Directory

This is the top-most directory in Linux.

Everything exists inside /.

/
├── home
├── bin
├── etc
├── usr

Think of / as the starting point of the entire system.

🧍 What is username? (Users in Linux)

Linux is a multi-user system, meaning:

• Multiple users can exist on one system

• Each user has their own space

When a user is created, Linux automatically creates:

/home/username

👉 This is the home directory of that user.

🏠 What is ~?

Instead of writing the full path:

/home/username

Linux provides a shortcut:

~

👉 ~ represents the current user’s home directory

So:

• cd ~ → goes to home

• pwd → shows /home/username .

👑 Understanding “root” (Very Important)

This is where many beginners get confused.

There are two meanings of “root” in Linux:

1. / → Root Directory Top of the filesystem Everything starts from here

2. root → Root User (Administrator) A special user with full control Can access and modify anything in the system.

Its home directory is:

/root

⚠️ Important:

• / ≠ /root

• / → whole system

• /root → admin user’s home

  ---

  Important Directories

  ---

  📦 /bin — Basic Commands

  👉 Command:

  ls /bin | head
  

  👉 Output:

  bash
  cat
  cp
  ls
  mkdir
  mv
  rm
  touch
  

  👉 These are basic commands used daily.

  ---

  ⚙️ /sbin — System Commands

  👉 Command:

  ls /sbin | head
  

  👉 Output:

  reboot
  shutdown
  mount
  fsck
  ifconfig
  

  👉 Mostly used by admin.

  ---

  📚 /usr — Installed Programs

  👉 Command:

  ls /usr
  

  👉 Output:

  bin
  lib
  share
  

  👉 Check programs:

  ls /usr/bin | head
  

  👉 Output:

  python3
  node
  gcc
  git
  vim
  

These are installed tools.

🏠 /home — Users

👉 Command:

ls /home

👉 Output:

user1
user2

👉 Enter a user:

cd /home/user1
ls

👉 Output:

Documents
Downloads
Pictures

📝 /etc — Configuration

👉 Command:

ls /etc | head

👉 Output:

passwd
hosts
hostname
group

👉 View users:

cat /etc/passwd | head

👉 Output:

root:x:0:0:root:/root:/bin/bash
user:x:1000:1000::/home/user:/bin/bash

👉 Shows user details.

🗑️ /tmp — Temporary Files

👉 Command:

cd /tmp
touch demo.txt
ls

👉 Output:

demo.txt

👉 File may disappear after reboot.

📊 /var — Logs

👉 Command:

ls /var/log | head

👉 Output:

syslog
auth.log
kern.log

👉 View log:

cat /var/log/syslog | head

👉 Output:

May 1 10:00:01 system started
May 1 10:01:22 login success

🔌 /dev — Devices

👉 Command:

ls /dev | head

👉 Output:

null
tty
sda
random

👉 Represents hardware.

⚡ /proc — System Info

👉 Command:

cat /proc/cpuinfo | head

👉 Output:

processor : 0
vendor_id : GenuineIntel
cpu MHz   : 2400.000

👉 Memory:

cat /proc/meminfo | head

👉 Output:

MemTotal:  8000000 kB
MemFree:   2000000 kB

🧠 Key Takeaways

• / is the root directory

• ~ is home directory

• Linux supports multiple users

• Each directory has a purpose

• Commands help explore everything

⚠️ Common Mistakes

• Confusing / and /root

• Running dangerous commands

• Ignoring system structure.