Strike Craft is a loosely used term in the Homeworld universe to describe ships that depend on larger ships (particularly carriers, shipyards, or motherships) for support and depend on speed and maneuverability to overwhelm larger opponents. For a large portion of their history strike craft also required refueling, their engines not based on the long-lasting fusion drives of larger ships. This changed however after the acquisition of the Acolyte Fighter Drive that allowed most strike craft to operate without refueling.
In most definitions fighters and corvettes are the two types of vessels listed primarily as strike craft. Strike craft generally have little armor and these ships generally were much less powerful than larger ships but had very good maneuverability and speed, making them vulnerable in front-on attacks but highly effective in harassment or swarm tactics. There are a few exceptions to this rule of course (most notably defenders and numerous corvettes).
During the Cataclysm Era however microships evolved as another kind of strike craft. Unlike fighters and corvettes, microships were not primarily used as combat vehicles but rather as support units. These ships were defined by the fact that they were very small, sometimes nearly invisible to visual sensors. All but one (the Sentinel) were also AI or remote controlled. By the Vaygr War these microships seem to have fallen out of favor however as all but basic auto-repair systems.
During the Beast War strike craft became more important than they had been in previous eras. Fighters such as the Acolyte were able now to take on Capital Ships of considerable size in relatively few numbers. This was due in part to the advance of the Acolyte Fighter Drive but also due to a technological boom in weapon design. This forced many capital ship designs to be reconsidered and by the Vaygr War capital ships now carried a substantial number of anti-strike craft weaponry.
The usage of strike craft has been a topic of discussion amongst major tactical minds throughout history. Prior to the Homeworld War when Fleet Intelligence discussed the possibility of hostile encounters with alien lifeforms Admiral Riif-sa and Fleet Admiral Paktu debated as to which was more important to a well-balanced fleet: capital ships or strike craft. Whereas Riif-sa argued in favor of capital ships Paktu argued for a strategy heavily dependent on strike craft.