ETL testing is done to ensure that the data has been loaded from a source to the destination after business transformation is accurate. It also involves the verification of data at various middle stages that are being used between source and destination.
Load runner is a performance testing tool. It is developed by mercury later acquired by HP. It is software testing tool used to test various applications, measuring system behavior and performance under load.
QTP stands for Quick Test Professional, a product of Hewlett Packard (HP). This tool helps testers to perform an automated functional testing seamlessly, without monitoring, once script development is complete.
Quality assurance (QA) is a way of preventing mistakes or defects in manufactured products and avoiding problems when delivering solutions or services to customers.