A mentor is someone who has expertise in a particular area and shares that learning with the mentee. Mentors provide knowledge, advice, guide, correct, and encourage in their field of expertise.
Consultants are specialists who are paid for solutions. They diagnose the problem and propose a solution. They often implement business strategies as well. Coaches also focus on solutions, but draw solutions out of the client. Coaches support the client in creating a plan of action and implementing it. Ultimately, clients gain long-term problem-solving capacity.