A life coach is someone that looks to empower others by helping them make, meet and exceed goals in both their personal and professional lives. A key aspect of life coaching is confidence.
Guidance is the life coach providing the tools and support for someone to broaden their perspective and open their mind, hence enabling them to reach their goals.
Empowerment is to a large extent down to the individual to realise their own self-worth and self-belief that has, for one reason or another, diminished.
And improvement in the sense that an individual will go from where they are to where they want to be, in effect reaching their goal.