To get any real benefit from the guide, the reader must have access (whether physical access or via SSH) [2] to a computer running Linux. Similarly, for the reader to benefit from sections in the guide that cover specific programs (such as Section 5.2, “GNU Emacs”), the software under discussion must be installed.
[2] Wikipedia's article on SSH describes it as "a network protocol that allows data to be exchanged using a secure channel between two networked devices." A discussion of SSH is beyond the scope of the guide, but the Wikipedia article may be helpful in learning more. If you're a student, you can try asking at the help desk at your school's computing center.