yum (Yellowdog Updater Modified) is a package management utility for PCs that are running the Linux operating system. It can be used to install, update and remove software packages from repositories. chmod (change mode) is a command that changes the permissions of files and directories in Linux. man (manual) is a command that displays the documentation of other commands in Linux. grep (global regular expression print) is a command that searches for patterns in text files in Linux. Verified Reference: https://www.comptia.org/blog/linux-package-management https://www.comptia.org/certifications/a