The load step of ETL is physically storing or presenting the result of the transformations in the target system.

Depending on the transformations performed, the target system’s purpose, and the intended use, the data may need further processing to be integrated with other data, or it may be in a final form, ready to present to consumers.

If the target system has more transformation capability than either the source or an intermediary application system, the order of processes may be switched to ELT – Extract, Load, and Transform. ELT allows transformations to occur after the load to the target system, often as part of the process. ELT allows source data to be instantiated on the target system as raw data, which can be useful for other processes. This is common in Big Data environments where ELT loads the data lake.