What is extraction, transformation, and loading?

It is a process of entering data, tracking data, and loading it into a database.

It is a process that extracts data from internal and external databases, transforms it using a common set of enterprise definitions, and loads it into a data warehouse.

It is a process that is performed at the end of the data warehouse model prior to putting the data in a cube.

It is a process that is performed at the beginning of all business processes.