There are a number of ways to customize Service Cloud to meet your exact needs. If we are talking about predefined editions, there are 4 basic types. Service Cloud Enterprise Edition is a comprehensive solution that provides a Lightning Console, a multichannel view of customer cases, CTI integration, scenarios for phone calls, enterprise knowledge base management, developer tools and other functionalities. With the Unlimited Edition you get, for example, unlimited access to online training materials, 24/7 free support and other services and functionalities. The Performance Edition then enables full integration of the store and customer support services. Current information on individual editions can be found on the official Salesforce website.