Since the 1980s there has been an increase in the use of  special operations  and special forces. Although some theorists would say that the use of special operation is as old as the art of war, the scientific study in this subject is not extensive. The author of this dissertation have identified that the concept special operations is defined in different ways and that there seems to be a discrepancy in how the concept is understood among theorists. Harry Yarger, who has written a theory of American special operations states that there is a difference in how other countries conduct special operations. If that is true, definitions of special operations should vary according to nation. The first purpose of this study is to examine chosen definitions of special operations and to identify what differs and what is similar. The second purpose is to see if there is a connection between how the concept is defined and a which category it belongs to. The studied definitions are here categorized according to studies of cases and/or doctrines from one specified nation or several nations. At least two different definitions were chosen in each category, that way the author could compare the definitions within a category to see if they are consistent with each other. By identifying differences and similarities the authors intent was also to find what traits links the three different categories in order to be able to develop a more uniform definition of the concept special operation. The analysis has shown that there are many differences between categories as well as within categories and therefore the conclusion is indecisive – the author has not been able to establish if or not the there is a connection between how the concept is defined and a category. However, those similarities found in every category has been used to make a suggestion to a more uniform definition of special operations: Special operations are of an unorthodox nature. The purpose of these operations are to solve significant political and military problems. Missions can include time limited attacks aiming to destroy, seize, recover or exploit chosen objects. Special operations are conducted by special forces.