An expert is someone who has a broad and deep expertise in knowledge, skills and experience through practice and academic prowess in a particular field. An expert is widely recognised as a reliable source of technique or skill whose faculty of judging or deciding correctly, justly or wisely confers authority and status on peers or the public in a specific, well-distinguished field. An expert, more generally, is a person within indepth knowledge or the ability based on research, experience or occupation and in a specific field of study. Experts are called upon to provide advice on their respective subjects. Experts do not always agree on the particulars of the field of study. An expert may be deemed, by his or her credentials, training, schooling, practise, publication or unparalled experience, to have unmatched knowledge of a subject beyond that of the average person, such that others may formally (and legally) rely on the opinion of the individual on that subject.