What is the difference between ecommerce analytics and reporting?

Reporting summarizes what already happened, in a fixed format: revenue by day, ROAS by campaign, sessions by week. Analytics investigates why performance moved and tells you what to do about it. That's what is the difference between ecommerce analytics and reporting in one sentence.

Reporting is descriptive and looks backward. Analytics is diagnostic, sometimes predictive, sometimes prescriptive, and it looks forward or at least sideways for a cause.