unix Basic console commands cd command, directories explained

Example

michael@who-cares:~$

The symbol ~ after the who-cares: is the current directory. ~ actually means the person's home directory. In this case, that's /home/michael.

michael@who-cares:~$ cd Downloads
michael@who-cares:~/Downloads$

Looks for Downloads in the current directory, then makes that the current directory.

michael@who-cares:~/Downlaods$ cd /var
michael@who-cares:/var$

Since this directory started with a /, that means look in the root directory for the directory var. For those coming from windows, the root directory is the equivalent to C:\. Directories starting with / are called "absolute directories" and directories that don't are called "relative directories"

michael@who-cares:/var cd lib/dbus
michael@who-cares:/var/lib/dbus$

The / in the middle means do cd lib and once that's done cd dbus in one command.

michael@who-cares:/var/lib/dbus$ cd .
michael@who-cares:/var/lib/dbus$

. actually means "the current directory". The command cd . is basically useless, but . is useful for other things.

michael@who-cares:/var/lib/dbus$ cd ..
michael@who-cares:/var/lib$

.. actually means "the parent of the current directory". As such, cd .. means "navigate one directory up".

michael@who-cares:/var/lib$ cd ../log/apt
michael@who-cares:/var/log/apt$

. and .. can also be part of the / chain. Also, there's no limit to how long it can be.

michael@who-cares:/var/log/apt$ cd /dev/bus
michael@who-cares:/dev/bus$

The / chain can even exist when the directory starts at root.

michael@who-cares:/dev/bus$ cd /
michael@who-cares:/$

cd / takes you to the root directory. I wonder what happens if you type cd .. here... (don't worry. It's safe)

michael@who-cares:/$ cd home
michael@who-cares:/home$ cd michael
michael@who-cares:~$

Every user has a directory for their stuff inside the home directory. If current directory is under the home directory, that part of the name, in this case /home/michael, it's replaced with ~.

michael@who-cares:~$ cd sys
michael@who-cares:/sys$ cd ~/Desktop
michael@who-cares:~/Desktop$ cd ~/..
michael@who-cares:/home$

~ can also be part of the / chain. It can even be in the same chain as ... If the directory starts with ~, it's an absolute directory just like if it starts with /.

Last thing to try: type cd with no directory after.