Service plans in Barracuda RMM have been set up to provide you with complete granularity over how you want to apply policies and services. For example, you can bypass service plans and apply a single service directly to a site, and you can apply a policy directly to a group. However, Barracuda RMM 10.0 and higher is designed with two service delivery models in mind: site-based delivery and group-based delivery.
Service plans are applied to an entire site. This service delivery method requires the least amount of configuration and maintenance, and is best used when you are providing very similar services to multiple customers.
Service plans are applied to site groups. Use this delivery method if you have structured your service offerings on a more granular level, i.e. you categorize your service offerings by device type, such as various services for servers, and various services for workstations. You can create shared site groups, which are site groups managed with a single group definition, to easily create and manage groups across your customer sites.