What are the Important things to test in eCommerce websites and mobile application?

Ecommerce mobile application and websites test is important to avoid compromise on many factors such as mobile responsiveness,user experience and customer data security,secure transaction and quick load time.For the eCommerce website success we have to give our customers a enjoyalbe and satisfying experience which depends on the proper functioning of the above factors.


Can you guys tell me the important factors to test in eCommerce mobile applications and websites?