You can think of a service as a project or a workspace that contains all the necessary configurations and components required to automate a particular use case or a customer journey.
Configurations include such things as the name of the service, a description, API key, your application URLs (to which platform events are posted) and the numbers, apps and integrations mapped to the service.
A service can optionally include components such as rules, flows, events and templates.
A dashboard and reports specific to the service are available within the service workspace.
For steps to create a Service, click here.
For more information on Service, refer the docs