ETL is an abbreviation of "extract, transform, load", which is a term used to describe the process of exporting data from one source and loading it into a different system in a different format. ETL tools are used to transfer data between relational databases, or simply to store data in data warehouses. Common examples of ETL tools include Micrsoft SQL Server Integration Services and Informatica ETL.

The alternative abbreviation ELT may be used when data is transformed before it is loaded.