People generally come together and join forces for a reason. In order to achieve the purpose effectively and efficiently, they create an organization. The sum total of those individuals’ shared beliefs, norms, attitudes, as well as skills is then reflected in the organizational values, vision, goals, systems, functions, policies, procedures and practices. It takes some time for this to develop, mature, and become universally accepted. This can then be loosely said to be that organization's culture.
By its very nature, culture ensures that its members continue to conform to the governing norms, assumptions and beliefs. To make any permanent significant change to the organizational systems, practices, or procedures, one has to modify the culture. Changing the culture is difficult, and it takes a concerted effort as well as time to do so. To some degree, the organization's culture is influenced by both internal factors (leadership, employees, and their interaction, which creates the work climate) as well as external (business, national, legal, global, etc.) factors. All cultures have specific subcultures.