OLTP vs. OLAP. We can divide IT systems into transactional (OLTP) and analytical (OLAP). In general we can assume that OLTP systems provide source data to data warehouses, whereas OLAP systems help to analyze it. The following table summarizes the major differences between OLTP and OLAP system design.
http://datawarehouse4u.info/OLTP-vs-OLAP.html