Which command would you use to manage services in a modern Linux system?

The command used to manage services in a modern Linux system is systemctl. This command is part of the systemd system management suite, which is the standard for initializing and managing system services in many contemporary Linux distributions.

With systemctl, users can perform a variety of actions on services, including starting, stopping, restarting, and checking the status of services. It also allows for enabling and disabling services to run at boot time. Systemctl provides a more consistent and comprehensive interface for service management compared to older tools.

In contrast, the service command, while still available in some distributions, is primarily used for backward compatibility with older init systems and may not offer the full range of capabilities provided by systemctl. The init command is associated with the older SysV init system, which has largely been replaced by systemd. Lastly, runlevel refers to a concept from older initialization systems that define the state of the machine during boot, but it is not used to manage services directly in modern systems.

Overall, systemctl is the preferred and most effective tool for managing services in today's Linux environments.