The /etc/resolv.conf file is used to define DNS name servers that the system uses for hostname resolution, so adding new DNS servers requires modifying this file.

This command creates a symbolic link at the specified path that points to the target directory, allowing access to the target through the new link location.

This command generates an SSH key pair and securely copies the public key to the remote server, enabling passwordless authentication by allowing key-based SSH login between the systems.

The journalctl command queries the systemd journal, and using -u app.service filters the output to logs generated by that specific systemd unit.

Kerberos provides centralized, ticket-based authentication and is the core authentication mechanism used by Windows Active Directory, allowing Linux systems joined to a Windows domain to authenticate users securely.