In short

Master Linux administration and security using the command line, GUI tools, Python, systemd, and firewalld
Set up key Internet servers, step by step, including Samba, Apache, MariaDB/MySQL, sendmail, OpenSSH, DNS, LDAP, and more. Including find, sort, xz (compression), free, xargs, and the nano editor

Full coverage of the LPI Linux Essentials exam objectives plus extensive coverage of the CompTIA Linux+ exam objectives.