How is a service started with 'systemctl'?

The command to start a service with 'systemctl' is 'systemctl start servicename'. This command is part of the systemd system and service manager, which is widely used in modern Linux distributions. When you use 'systemctl start servicename', it instructs systemd to initiate the specified service. If the service is configured properly, this will load it into memory and execute it, making it active and ready to perform its designated tasks.

Understanding the use of 'start' is crucial as it directly impacts the state of services running on the system. It can enable services to contribute to system functionality, such as running a web server, database, or other critical components. The terms 'launch', 'begin', and 'execute' are not valid commands in the context of systemctl, hence they do not initiate services correctly in systemd. The specificity of the command structure is important for proper service management on Linux systems.