This is the service details page. Use this page to modify the meta-data, plans, and policies for the service. There is no need to follow the tabs in order, but note that you will need to fill out a minimum amount of data before the service can be published to the Gateway. In particular, the Implementation and Plans tabs are important (more information below).
The 'Implementation' tab is where you go to configure the details of the real service being managed. This is where you tell apiman where the service is, so that we can actually invoke it at runtime.
The 'Definition' tab allows you to configure an optional Service Definition document for your service. A Service Definition is a detailed description of the capabilities of your Service (operation names, http verbs, data models). For example, you might add a Swagger spec document as your Service Definition.
The 'Plans' tab is used to configure which Plans (already defined in the Organization) are available when an Application wishes to create a Service Contract with this Service. Optionally, a Service can also be marked as "Public", which means that no Service Contract is required (the Service can be invoked without sending an API Key).
The 'Policies' tab is where you go if you wish to configure any policies that should be enforced for *all* requests to the Service, regardless of which user, application, or plan is being used. In other words, Service-level policies.
The 'Contracts' tab will show a table of all Applications that have created Service Contracts to this Service. In other words, it shows all of the registered consumers of the Service. Note that if the Service is marked as "Public", this tab will likely be empty.
The 'Endpoint' tab will show you information about how to invoke the Service once it is published to the API Gateway.
The 'Activity' tab shows a history of all the changes made to the Service. Essentially it is an audit log.