A data mart is a data storage system that contains information specific to an organization's business unit.
It contains a small and selected part of the data that the company stores in a larger storage system.
3 Types of Data Marts.
There are fundamentally three types of data marts: dependent, independent and a combination of the two called hybrid.
What they have in common is that all three present a subject-specific set of data to the business teams that will benefit most from that particular dataset.
OLAP means anlytical rather than transactional data and you are looking at the data stored in a cube.
Data Mart is a collection of data that may come from many sources and is a little data warehouse in its own right.