Introduction to the Linux Shell -

The cdcommand stands for "change directory" and is how you move between folders in the Linux shell. When you open a terminal, you start in your home folder, and cd lets you navigate to any other folder on the system. You can move into a subfolder with a name like Documents, go back to the parent folder with cd .., or jump straight to your home folder with cd ~. You can also use full paths like cd /tmp to go anywhere, or use cd - to return to the folder you were just in. Mastering cd is essential because every other command you run depends on being in the right place.

• The simplest way to use cd is to type it followed by the name of a folder inside your current directory.
• For example, cd Documents moves you into the Documents folder.
• After you run cd Documents, the prompt changes to show you are now inside the Documents folder.
• You can verify your new location by typing pwd, which prints the current directory path.
• Type cd Documents to move into the Documents folder and see how the prompt changes.

• The special name ..means "the parent folder" — the folder that contains the current one.
• If you are inside Documents, typing cd .. takes you back to your home folder.
• You can chain multiple .. levels together like cd ../.. to go up two levels at once.
• The .. entry exists in every folder and is created automatically by the filesystem.
• Try cd .. to move up one level from wherever you are.

• The tilde character ~is a shortcut that always means "your home folder."
• Typing cd ~ from anywhere in the filesystem will return you to your home folder.
• Your home folder is usually /home/user in this simulator.
• Using ~ is faster than typing the full path /home/user every time.
• You can also use ~ with other paths, like ls ~/Documents, to refer to folders inside your home directory.

• An absolute path starts with a forward slash / and describes the full location from the root of the filesystem.
• For example, /tmp is the full path to the temporary files folder, no matter which directory you are currently in.
• Absolute paths always work the same way, regardless of your current location.
• This is different from a relative path like Documents, which only works if Documents exists inside your current folder.
• Type cd /tmp to jump directly to the temporary folder using its absolute path.

• You can use an absolute path with cd to jump directly to any folder on the system.
• cd /home/user/Documents takes you straight to the Documents folder using its full path from the root.
• Absolute paths always start with / and work from any location.
• This is useful when you know exactly where a folder is and want to go there without stepping through each parent.
• Try cd /home/user/Documents to move directly to your Documents folder from anywhere.

• A relative path like ../var combines the parent shortcut .. with a folder name to navigate.
• From your home folder /home/user, cd ../var goes up to /home and then into /home/var.
• You can chain as many path parts as you need, like cd ../../etc to go up two levels and then into etc.
• Relative paths are flexible because they work from wherever you are standing.
• Try cd ../var to practice moving up one level and then into a different folder.