What is Wave namespace in salesforce?

Hi Laveena,

The classes in the wave namespace are part of the Wave Analytics SDK, designed to facilitate querying Wave data from Apex code.

The following are the classes in the wave namespace.
QueryBuilder Class
The QueryBuilder class provides methods for constructing well-formed SAQL queries to pass to Wave Analytics.
QueryNode Class
Define each node of the query - such as projection, groups, order, filters. Execute the query.
ProjectionNode Class
Add aggregate functions to the query, or define an alias.