Runabout is a generic term for a spacecraft that falls in between Shuttlecraft and full sized Starship.
Usually intended for short duration, limited distance interstellar flights, these ships typically carry no more than a dozen people and usually 2 - 6 for a long trip. Technical Specifications and capabilities vary.
Runabouts serve two purposes. They seperate the main protagonists from the rest of the ship and limit the resources available to solve problems with. They also allow subsidiary characters to take off and have side stories on their own.