Data extraction is a process that involves the retrieval of data from various sources. Frequently, companies extract data in order to process it further, migrate the data to a data repository (such as a data warehouse or a data lake) or to further analyze it.

• Full extraction- Data is completely extracted from the source, and there is no need to track changes. The logic is simpler, but the system load is greater.
• Incremental extraction- Changes in the source data are tracked since the last successful extraction so that you do not go through the process of extracting all the data each time there is a change. To do this, you might create a change table to track changes, or check timestamps.