Extract, Transform, Load (ETL) in IT means to combine data from several data sources and with different structures in a target data bank. This procedure consists of three steps, from which the term “ETL” comes:
- Extraction (extract) of the relevant data from different sources
- Transformation (transform)
- Loading (load) of the data into the target data bank
The pocess is used primarily in a warehouses mode. Large data volumes are collected from several operational databases and then stored in a data warehouse.