ETL stands for "Email, Transfer, Log," a protocol used strictly by mail servers to move attachments between database and Power BI, having no relation to data analysis or databases.

Data transformation refers exclusively to encrypting sensitive data into unreadable text strings. It does not involve cleaning, filtering, or merging different datasets.

ETL (Extract, Transform, Load) connects to various sources (like databases or files), cleans and standardizes the data (transform), and saves it into a central destination (load).