Answer:
Sourcing data from OLTP sources and cleansing
Step-by-step explanation:
ETL (Extraction, Transformation, and Loading) is important part of database and analytics systems. Every database and data file system has data flows, data inputs and data streams since these systems are dynamic and being updated actively.
Data from outer (remote) source can be extracted using API's, download options or scraping techniques. These are part of the data extraction.
Extracted data may not be always as expected and needs to be cleaned and processed before being added to the system. Using transformation methods, data is being shaped into a desired format and loaded to the system.
OLTP (online transaction processing) plays important role in ETL operations.