Neck knives are easy to carry and can be carried around the neck with a cord or chain as a necklace. The knife will not be obvious to others and thus can be used as survival and self-defense knife.
They are usually a small or medium size knife which is comfortable to carry around the neck. The string of a neck knife will not be too long which may not be comfortable for the user.
Neck knives opt for its easily accessible property. When you are in outdoor activities like hunting, camping or any tactical work, neck knives are easily reachable.