Found another useful information highlighting difference between OLAP and OLTP in Delivering business intelligence with SQL Server 2008 by Brian Larson.
OLTP build around the normalized data and dependencies are represented by complex foreign key relationships; the goal is to reduce redundant data. In OLAP just the opposite is true.
The OLAP is represented by dimensions and hierarchies. If the OLAP system is designed properly, these dimensions and hierarchies should match the structure of an organization resultantly decision makers are familiar with the data structure.
[...] Reports 2008 is a reporting tool which can access and present data from Relational Databases and OLAP follwing are the supported OLAP databases: Hyperion Essbase Seagate Holos and Seagate INFO/Crystal [...]