An outstanding problem in the physics of high-TC cuprates is to understand the relation between the superconductivity and competing orders.  Recently significant insight into this problem has been provided by the observation of charge density wave (CDW) order in YBa2Cu3O6+x (YBCO), indicating that CDW order is likely generic to cuprates.  In this talk I will detail resonant soft x-ray scattering measurements of the CDW order in both YBCO and the La-based cuprates, highlighting the similarities and differences between CDW order in different compounds.  I will also discuss the implications of these measurements to understanding the competition between superconductivity and CDW order, and the microscopic character of the CDW order.