Online Transactional Processing (OLTP) refers to day to day operations. Whereas OLAP refers to Managerial operations. OLTP is application oriented, OLAP is subject oriented.
A BI system is a solution for gathering the operational data or external source of data and transforming it to a consistent form and stored in a single location and presenting the information for analysis and decision making.
Microsoft SQL Server gives all the scalability of Business Intelligence. Just look at this picture,