Simplify the following text for a Grade 10 native English-speaking person.
Original: Sled dogs , known also as sleigh man dogs , sledge dogs , or sleddogs , are highly trained types of dogs that are used to pull a dog sled , a wheel-less vehicle on runners also called a sled or sleigh , over snow or ice , by means of harnesses and lines .
Simplified: Sled dogs , known also as sleigh dogs , sledge dogs or sleddogs are types of dogs that are used to pull a wheel-less vehicle on runners ( a sled or sleigh ) over snow or ice , by means of harnesses and lines .