SQL Server 2012 is has very exciting new feature of SQL Server AlwaysOn. This new feature reduces planned and unplanned downtime and maximize application available. Additionally it provides data protection keeping database always available. Microsoft has released a whitepaper on this subject where it discusses common context business stakeholders, technical decision makers, system architects, infrastructure engineers, and database administrators.
This whitepaper discusses two major points. Following is the abstract from book online:
High Availability and Disaster Recovery Concepts. Provide a brief discussion of the drivers and challenges of planning, managing, and measuring the business objectives of a highly available database environment. This discussion is followed by a brief overview of the high availability and disaster recovery capabilities of SQL Server 2012 AlwaysOn and Windows Server solutions.
SQL Server AlwaysOn Layers of Protection. Provide a deeper discussion of the feature capabilities, rationale, and dependencies of the layers of protection offered by a SQL Server AlwaysOn solution. It will cover infrastructure availability, SQL Server instance-level protection, database-level protection, and data tier application capabilities.
Reference: Pinal Dave (https://blog.sqlauthority.com)