The terminal looks intimidating, but it's really just a text box for telling your computer to do things. These ~20 commands cover most of what anyone does every day. Learn them once and you'll use them forever.

1. Finding your way around

pwd              # print working directory — where am I?
ls               # list files in the current folder
ls -la           # list everything, including hidden files (a = all, l = details)
cd folder        # change directory — go into a folder
cd ..            # go up one folder
cd ~             # go to your home folder
cd -             # go back to the previous folder you were in

cd is the one you'll type most. Remember: .. means "parent folder" and ~ means "home".

2. Working with files

cp source dest   # copy a file
mv source dest   # move (or rename) a file
rm file          # delete a file
rm -r folder     # delete a folder and everything inside it (careful!)
mkdir folder     # make a new folder
touch file       # create an empty file
cat file         # print a file's contents
less file        # view a file page by page (q to quit)
nano file        # edit a file in a simple editor (Ctrl+O save, Ctrl+X exit)
There is no undo for rm. It's the terminal equivalent of dragging something into the void. Always double-check the path before you press Enter.

3. Permissions (why Linux asks who you are)

Linux is built around users and permissions. Every file has an owner and access settings — read, write, execute — for the owner, their group, and everyone else. 

ls -l            # shows permissions (like -rw-r--r-- and the owner)
chmod +x file    # make a file executable
chown user file  # change a file's owner
sudo command     # run a command as administrator

sudo ("superuser do") is how you install software or change system settings. Only use it when a command fails with a permission error — and always know what the command does first.

4. Installing software (package managers)

Linux installs software through a package manager. The command depends on your distro family: 

# Debian / Ubuntu / Mint
sudo apt update && sudo apt upgrade   # update everything
sudo apt install package-name         # install
sudo apt remove package-name          # remove

# Fedora / RHEL family
sudo dnf upgrade                      # update everything
sudo dnf install package-name         # install
sudo dnf remove package-name          # remove

Install && means "run the first, and if it succeeds, run the second". Updating first keeps the package lists current.

5. Pipes: the terminal superpower

The | character (a pipe) feeds one command's output into the next command. This is where the terminal becomes magical: 

ls | wc -l        # count how many files are here
history | tail   # show your recent commands
grep error log.txt   # search a file for "error"
ps aux | grep firefox # find running Firefox processes

grep deserves its own medal — it searches text for a pattern. You'll use it constantly.

6. Looking around the system

top              # live view of running processes (q to quit)
htop             # friendlier version of top (if installed)
df -h            # how full are my disks? (h = human-readable)
free -h          # how much RAM is in use?
uname -a         # what kernel am I running?
ip a             # my network addresses
ping google.com  # is the internet reachable? (Ctrl+C to stop)

7. Quick tips that save time

A tiny real-world session

Here's everything above working together:

$ cd ~/projects
$ mkdir mysite
$ cd mysite
$ touch index.html
$ ls -la
$ nano index.html          # type some HTML, Ctrl+O, Ctrl+X
$ grep -i "title" index.html   # did I write a title?
$ cd ..
$ rm -r mysite            # oops — no undo from here

You don't need to memorize any of this — man and the tab key will carry you. Just keep these handy and the terminal stops being scary and starts being your favorite tool.