Specialist or Expert
ex•pert [n., v. ek-spurt] a person who has special skill or knowledge in some particular field; a person with a high degree of skill in or knowledge of a certain subject; authority; possessing special skill or knowledge; trained by practice; skilful or skilled; having, involving, or demonstrating great skill, dexterity, or knowledge as the result of experience or training.
spe•cial•ist [spesh-uh-list] a person who devotes himself or herself to one subject or to one particular branch of a subject or pursuit.
In 8578 you will find more specialists than experts.
