What does a Chief Marketing Officer actually do?

What does a Chief Marketing Officer actually do?
A CMO translates business strategy into go-to-market execution and owns the function across demand generation, product positioning, brand stewardship, and customer marketing. The role is not the head of advertising. It is the executive accountable for revenue generation from a marketing system. For most companies under 20 million in revenue, a Fractional CMO delivers that ownership without the full-time cost.