The Service Skiff is a small spacecraft, typically found aboard Conestoga-class starships. Service Skiffs can be used as scout ships, sent ahead of the Conestoga-class ship to provide reconnaissance.
The Service Skiff is not intended for long voyages, and can only be used for about a two day trip in space. Skiffs are capable of entering a planet's atmosphere and landing on the ground which they have landing gear for.
Conestoga-class starships have ports on the sides near the front of the ships which Service Skiffs can connect to and presumably board the ship from.