A black operation (or black op) is a covert operation or clandestine operation by a government agency, a military unit or a paramilitary organization. This can include activities by private companies or groups. Key features of a black operation are that it is secret and it is not attributable to the organization carrying it out. The main difference between a black operation and one that is merely secret is that a black operation involves a significant degree of deception, to conceal who is behind it or to make it appear that some other entity is responsible ("false flag" operations).