Terminology
A cube can be considered a generalization of a two-dimensional spreadsheet. For example a company might wish to summarize financial data by product, by time-period, by city to compare actual and budget expenses. Product, time, city and scenario (actual and budget) are the data's dimensions.
Cube is a shortcut for multidimensional dataset, given that data can have an arbitrary number of dimensions. The term hypercube is sometimes used, especially for data with more than three dimensions.
Each cell of the cube holds a number that represents some measure of the business, such as sales, profits, expenses, budget and forecast.
OLAP data is typically stored in a star schema or snowflake schema in a relational data warehouse or in a special-purpose data management system. Measures are derived from the records in the fact table and dimensions are derived from the dimension tables.
Read more about this topic: OLAP Cube