The phrase "uncharted territory" refers to a place or situation that has not been explored, mapped out, or experienced before. It is an area where there are no established guidelines, rules, or precedents, and it can be characterized by uncertainty, risk, and the unknown. People may feel apprehensive about venturing into uncharted territory because of the lack of information and the potential for danger. However, it can also represent new opportunities and possibilities that have yet to be discovered.