In military science, the term commando can refer to an individual, a military unit, or a raiding style of military operation. In some contexts, "commando" means elite light infantry or special forces. In some countries such as the UK and Australia there is a distiction between Commandos, who tend to operate in company or larger formations in offensive or direct action tasks and Special Forces, who tend to operate in smaller formations and specialize in the training of indigenous guerillas, strategic/special reconnaissance missions behind enemy lines or more recently counter-terrorism. It should be noted that the two terms are by no means mutually exclusive and in some countries they are synonymous (eg the GCMA was a classic example of a what in anglo-saxon terms would be a SF unit).
Originally "a commando" was a type of military unit. In many languages, "commando" or "kommando" means "command", in the sense of a military unit.
Commando units have a variety of specialist capabilities which enable them to conduct these kind of operations, most notable a broad range of deployment skills which often include parachuting, airborne rappelling or fast-roping, or amphibious landings.