Insubordination is the act of a subordinate deliberately disobeying a lawful order. Refusing to perform an action that is unethical or illegal is not insubordination; neither is refusing to perform an action that is not within the scope of authority of the person issuing the order. Insubordination is typically a punishable offense in hierarchical organizations which depend on people lower in the chain of command doing as they are told.
A hierarchical organization is an organizational structure where every entity in the organization, except one, is subordinates to a single other entity. This arrangement is a form of a hierarchy. In an organization, the hierarchy usually consists of a singular/group of power at the top with subsequent levels of power beneath them. This is the dominant mode of organization among large organizations; most corporations, governments, and organized religions are hierarchical organizations with different levels of management, power or authority.
For example, the broad, top-level overview of the general organization of the Catholic Church consists of the Pope, then the Cardinals, then the Archbishops, and so on. Members of hierarchical organizational structures chiefly communicate with their immediate superior and with their immediate subordinates. Structuring organizations in this way is useful partly because it can reduce the communication overhead by limiting information flow; this is also its major limitation.
Military Insubordination is refusal by a subordinate to obey lawful orders given by a commissioned officer or non commissioned officer (NCO). Refusal of a military officer to obey his (civilian) superiors would also count, although in some nations, the head of the government is (at least technically) also the most superior officer of the military (see for example Commander in Chief).
Generally, an officer or soldier is expected to be insubordinate to the point of mutiny if given an unlawful order, however. In the U. S. military, insubordination should not be confused with contempt. While insubordination deals predominately with not following the orders of a superior, contempt in the U. S. military involves the use of contemptuous words against certain appointed or elected officials, as detailed in Article 88 of the military codebook.