Universities, banks, and hospitals are all institutions. Until you arrived at the bank, you'd forgotten that financial institutions were closed for the holiday. Thank goodness for the ATM! The noun institution also refers to a long held custom or practice in society. Even if your parents divorced when you were young, you might strongly believe in the institution of marriage. Or you might believe that once you enter the institution of marriage, your next stop will probably be a mental institution.
A consultant (from Latin: consultare to deliberate) is a professional who provides expert advice in a particular area such as security (electronic or physical), management, education, accountancy, law, human resources, marketing (and public relations), finance, engineering, science or any of many other specialized fields.
Experienced professional who provides expert knowledge (often packaged under a catchy name) for a fee. He or she works in an advisory capacity only and is usually not accountable for the outcome of a consulting exercise. Some consultants (like Peter Drucker and W. Edward Deming) have brought dramatic shifts in management thinking and improvements in the performance of organizations.