What is 'external system' in SAP BW - SAP Business Information Warehouse?

external system - Overview

• Component: BW

• Component Name: SAP Business Information Warehouse

• Description: SAP-external data source for a BI system that uses staging BAPIs to transfer data and metadata.

external system - Details

• 
  Key Concepts: 
  An external system is a system that is not part of the SAP Business Information Warehouse (BW) but can be connected to it. This connection allows data to be exchanged between the two systems. The external system can be a database, an application, or any other type of system. 
  
  How to use it: 
  In order to connect an external system to BW, you must first create a connection between the two systems. This is done by creating an RFC (Remote Function Call) connection. Once the connection is established, data can be exchanged between the two systems. 
  
  Tips & Tricks: 
  When creating an RFC connection between an external system and BW, make sure that the data types are compatible. If they are not, then data may not be exchanged correctly. Additionally, make sure that the security settings are configured correctly in order to ensure that data is secure when being exchanged between the two systems. 
  
  Related Information: 
  For more information on connecting an external system to BW, please refer to SAP's documentation on RFC connections. Additionally, there are many tutorials available online that provide step-by-step instructions on how to create and configure an RFC connection.