The Interceptor Series is a design which dates back to the Old Republic and started with a fairly simple combat airspeeder for atmospheric defence of groundtargets (the mk.1).
As such they became fairly popular with law enforcement agencies, who however boosted its possibilities to be able to pursue criminals into space. Something which MandalMotors improved upon with the next version. (the mk.2). With the start of the Clonewars they were upgraded to become fully functional starfighters (the mk.3) before the design was left entirely in favour of its sucsessor, the Pursuer Enforcement Craft - which was designed as a starfighter from the start.

When landed, the wings can be folded up to the sides of the craft for more efficient storage; when folded, two Interceptors can be stored inside a standard 2000 cubic metre transport container. Because of this their use in the Empire continued in a different role:
Close Air Support and Anti-Armour fighterbomber launched from AT-ATs. They even saw action on Hoth in this fashion. To be able to take down armoured vehicles the two regular laser cannons on the wings were replaced by a heavier one up front. (the mk.4)

The Empire soon after replaced these with newer designs. They can however, still be found on many planets in the Outer Rim, in the hands of law enforcement agencies, Rebels, Pirates and bounty hunters. Some of which might have added hyperdrives or shields, some of which might even be based upon the Mk.1 (atmospheric) or Mk.2 (mostly atmospheric) versions.