cd practice
Changes the directory to practice.
mkdir mysubdirectory
Creates a subdirectory of practice.
cp /etc/profile .
cp is short for “copy.” /etc/profile is just a random file on your system, don’t worry about what it is for now. We’ve copied it to . (recall that . just means “the directory I’m in now,” or the current working directory). So this creates a copy of /etc/profile and puts it in your practice directory. Try typing ls to verify that there’s indeed a file called profile in your working directory, alongside the new mysubdirectory.
more profile
This lets you view the contents of the file profile. more is used to view the contents of text files. It’s called more because it shows one screenful of the file at a time, and you press the space bar to see more. more will exit when you get to the end of the file, or when you press q (quit).
more /etc/profile
Verifies that the original looks just like the copy you made.