ETL stands for Extract, Transform, Load, and it is a process used to extract data from one or more sources, transform it into a consistent and clean format, and load it into a target system or database. ETL tools are software designed to support ETL processes, and they automate and simplify the process of extracting data from various sources, transforming it into a consistent and clean format, and loading it into the target system in a timely and efficient manner. ETL tools are used to modify and move business data, and they simplify data management strategies and improve data quality by providing a standardized approach to intake, sharing, and storage.

There are different types of ETL tools, including enterprise software ETL tools, open-source ETL tools, and general-purpose programming languages. Enterprise software ETL tools are developed and supported by commercial organizations, and they tend to be the most robust and mature in the marketplace. Open-source ETL tools are free to use, and their source code is also freely available, which allows users to extend or enhance their capabilities. General-purpose programming languages offer the greatest flexibility, but they require the most effort.

ETL tools are typically used by a broad range of professionals, from students in computer science looking to quickly import large data sets to database architects in charge of company account management. ETL tools have started to migrate into enterprise application integration, or even enterprise service bus, systems that now cover much more than just the extraction, transformation, and loading of data.