Extract, Transform, Load (ETL) is a data processing framework used to gather data from various sources, such as databases, spreadsheets, or APIs. The "Extract" phase involves retrieving this data, which can be structured or unstructured, from its original location. Once the data is extracted, it undergoes the "Transform" phase, where it is cleaned, organized, and converted into a suitable format for analysis. Finally, in the "Load" phase, the transformed data is stored in a target system, like a data warehouse, making it accessible for reporting and analysis.