Cruisers are by far the most numerous and varied craft in most space navies, and come in many sizes and varieties including Heavy, Command, Medium, Supplemental, Light, Research and Medical Cruiser types amongst others. One of the oldest designations, the term Cruiser refers to a large array of vessel types and sizes. Cruisers can be both general purpose and mission specific, with many capable of autonomously switching between the two extremes when needed.
Cruisers are not as large or powerful as Battleships or Dreadnoughts, but can often be as effective in military conflict. Cruiser are also highly varied in their abilities to explore and expand the boundaries of established governments. First contacts, stellar and planetary research as well as diplomatic negotiations are all well within the purveyance of Cruiser class vessels. Cruisers can also easily switch to medical emergency mode, search and rescue and evacuation when needed. Most cruisers have a large science base, consisting of numerous sensor system, independent science labs and numerous on-board departments that specialize in a wide variety of space and planetary science.
Cruisers often have a large engineering contingent, giving a cruiser unique forward capabilities while in deep space. Cruisers can maintain lengthy patrols and explore well beyond the boundaries of established boarder space. Cruisers are often well armed and very capable of defence and combat when necessary. Cruisers are the mainstay of the Romulan Navy, and an expansive part of the Federation and Klingon Navies.