Show the types of filesystems currently in use. Show the setup of printers. Show the kernel modules currently loaded. This command can be used to show other environment variables as well. Try man man first.
Manual pages can be hard to read.
Give me the list of the commands that have something to to do with my topic. The same command is used for moving and renaming files and directories. Create a hard link called destination to the file called source. Any changes the file are automatically visible throughout. The symbolic link just specifies a path where to look for the file.