ETL stands for Extract, Transform, and Load, it is the process in data warehousing that is responsible for pulling data out of the source systems and placing it into a data warehouse.
Basically, Extract, Transform, and Load, are three database functions that are combined into one tool that can be used to pull data out of one database and put it into another one.
Extract is the process of reading data, Transform is the process of converting the extracted data from its previous form into the new one that it needs to be in so that it can be placed into another database.
Load is where the data is written into the target database.
ETL is an extremely important element of the migration of database to another database.
Numerous ETL tools are available from the likes of IBM with Websphere DataStage, Informatica PowerCentre, Oracle ETL, Pentaho Data Integration, and Microsoft SQL Server Integration Services.
