Organizational culture is more of a larger picture, a more general term that refers to a large umbrella of smaller topics and issues within an organization. The structure refers to the infrastructure and the various methods and practices within that infrastructure. That helps an organizational culture run with the efficiency and consistency which should be the hallmark of any healthy organizational structure, whether it is in a corporation, sports team, or any other set up that is large enough to create its own organizational culture.
This makes the structure an integral part of any organizational culture, but also narrows out a very specific segment of the culture as its own responsibility. Organizational structure will deal primarily with the set up of the culture. How management works, which specific responsibilities supervisors have, how a complaint is passed through the ranks-these are all issues within the organizational culture that are directly tied to how an organizational structure works. The structure is not limited to those three examples, but it would certainly include all of them.
Another common way to describe how structure works is to say that organizational structure is the way in which the interrelated groups within and organization are set up to allow them to function smoothly from a larger standpoint. The two main purposes of a successful organizational structure is to ensure effective communication between various parts of the company, as well as to increase coordination between different departments.