To open a terminal window. Usually a right mouse click on the main Linux window, then a left mouse click on “Open_Terminal”. Many LINUX commands can be modified with descriptors that change how the command output appears, or how the command works. View ls and ls -rtl below.

pwd present working directory tells dir level

cd ../ change directory going up one level

cd dirname change directory going down to the newly specified directory

cp existingfile newfile
cp an existing file to a new file with a name of newfile

ls list files in a directory

ls -rtl list files in a directory
-r reverses order, -t sort by modification time newest first, -l long listing format

du disk usage

du -h disk usage
-h human readable uses K kilobytes, M megabytes, G gigabytes