SharePoint 2013 includes three new services:
• App Management Service. SharePoint Server 2013 has embraced the app model, which has become so familiar to mobile device users over the last few years. SharePoint Server 2013 provides a platform for in-house or third-party apps to be used across an organization, with the service application managing permissions and access to individual apps.
• Machine Translation Service. The growth of SharePoint as a global platform is enhanced with the new Machine Translation Service application. This provides automatic language translation of document and site pages. This does not mean that SharePoint Server 2013 itself provides a translation engine. When the Machine Translation Service application processes a translation request, the request is forwarded to a cloud-based host that performs the actual translation. This is designed to integrate with the existing Variations functionality.
• Work Management Service. For business users, this service is designed to provide an integrated view of their work. The tasks that users need to undertake are aggregated on the users’ My Site. These tasks may be from the SharePoint server, or they may be from external systems, such as Microsoft Exchange or Microsoft Project Server. The architecture of the Work Management Service is such that it will be able to aggregated tasks from other environments in the future. Services that have been deprecated or changed in SharePoint 2013 include:
• Web Analytics Service. Rather than have this as a self-contained service application, the Web Analytics functionality has been incorporated into the Search service.
• Office Web Apps Service. Office Web Apps is now a separate server product.
A small farm have between two and approximately five servers,can serve between 10,000 to 20,000 users depending on usage and service requirements.
Medium farms : These farms have between approximately five and 10 servers, separated into three tiers. Can manage up to 40 million items.