What is the role of SAP BW?

Question

SAP

Hello. I'm trying to figure out the basic SAP tools. I do not quite understand the role of SAP BW (hereinafter referred to as BW).
BW is a database, that is, all information is constantly stored in it, and SAP ERP only collects information? Or not? Judging by this picture, BW is an aggregator, that is, simply a manager of information stored in the database. But in this picture, the roles of the DB and BW are reversed (their order in the chain). So what is the essence of BW and what place does it take?

Answer 1

aggregation and adaptation of incoming data

Answer 2

Yes... It will take you a long time to sort through the advertising booklets of marketers.
Better google.
Here is the very first conclusion:
SAP BW is a platform that allows you to store huge amounts of business information and use it to analyze the situation and make informed management decisions.
Actually this is the essence. We store the BI and analyze it (different angles), then we show the big bosses what happened. However, it doesn't have to be big.