What is mental health?
well mental health is a way to describe your mental "well being"
Ok. Is it the mental state of a person?
yeah basically! it's a measurement of how a person is doing emotionally and how well their behavior is as well
Does it tell a person's psychological well being too? 
yes because it's how well an individual can enjoy their life! Like can they create a balance between mental resilience and life activites
That is true.
there's a lot of cultural differences as to what mental health defines