This document discusses Linux environment variables, package management using RPM and dpkg, managing services, and provides a lab exercise on installing and configuring Apache HTTPD. It explains that the PATH variable specifies the program execution path in BASH. Modifying PATH requires updating .bashrc or /etc/environment for persistence after reboot. Package management tools RPM, YUM, DNF and dpkg are covered along with common commands. Managing services with systemctl and service is also summarized, including starting, stopping, restarting, checking status, and setting services to start at boot. The lab exercise has steps to install, configure and test Apache HTTPD.