What is the difference between unknown and uncharted ?Feel free to just provide example sentences.

Uncharted means that there is not a chart, or a map, of an area. It is a term sailors use. "These are uncharted seas." meaning they are traveling into unfamiliar waters without a map to help them.
Unknown is a more general term and can mean the same thing ("This is unknown territory"), plus is used in many other situations.
Uncharted can also be used as a metaphor when you aren't talking about a literal map. "We are entering an uncharted part of the human mind", "This book takes us into uncharted levels of terror." It means no one has explored and written about this before.