In SQL Server 2012 Microsoft introduced the BI Semantic Model (BISM). BISM encompasses the different deployment options for Business Intelligence within SQL Server 2012.
The highest level of choice is between Multi-dimensional Analysis Services and Tabular. Multi-dimensional is the newest version of the hierarchical Analysis Services model. It's been used a lot since SQL Server 2000, and it was changed a lot in SQL 2005 and 2008. Tabular is a new deployment option specific to SQL 2012 and is based around tables rather than hierarchies.
MDX is the query language for hierarchical cubes, and continues to be used to query SQL 2012 Multi-dimensional. It can also be used to query Tabular models, which have been deployed to the xVelocity in-memory engine within Analysis Services. Tabular models, which have been deployed this way can be queried by any MDX-generating client tool, or also through the DAX language.
Tabular models can also be deployed using Direct Query mode, but these can only be queried through DAX, and not MDX. In terms of the native client tools for SQL 2012, Pivot Tables use MDX, and PowerView uses DAX. To connect to all the BISM deployment modes, you would need both Pivot Tables and PowerView. Anaplan XL thought users would like a consistent experience, no matter what type of BISM they were using.
Refer to Tabular for more information.
