PWD is not short for PASSWORD, it may seem like it but in Linux and therefore Ubuntu, PWD stands for “print working directory” and that is exactly what this command is going to do, display the name of the current working directory ( the current directory you are in ) on Ubuntu’s Terminal, printing the full path on the results. just like Breadcrumbs on webpages.
You can check your present working directory in title bar of Gnome Terminal’s window
The ~ symbol is shorthand in Linux for your User’s home directory. If you type cd~ you will change back to your home directory. It saves you time from having to type out cd/home/username
If you are more of a visual person, check out this video on how to use the pwd command in UBUNTU