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.
A consultant is usually an expert or an experienced professional in a specific field and has a wide knowledge of the subject matter. The role of consultant outside the medical sphere (where the term is used specifically for a grade of doctor) can fall under one of two general categories:
Internal consultant: someone who operates within an organization but is available to be consulted on areas of their specialization by other departments or individuals (acting as clients); or
External consultant: someone who is employed externally to the client (either by a consulting firm or some other agency) whose expertise is provided on a temporary basis, usually for a fee. Consulting firms range in size from sole proprietorships consisting of a single consultant, small businesses consisting of a small number of consultants, to mid- to large consulting firms, which in some cases are multinational corporations. This type of consultant generally engages with multiple and changing clients, which are typically companies, non-profit organizations, or governments.
The range of areas of expertise covered by the term "consultant" is wide. One of the more common types is the management consultant. Consulting and the means by which the (external) consultant is engaged vary according to industry and local practice. However the principal difference between a consultant and a temp is generally one of direction. A consultant or temp is engaged to fulfill a brief in terms of helping to find solutions to specific issues but the ways in which that is to be done generally falls to the consultant to decide. An information systems or project management consultant is also referred as just a consultant who manages constraints such as budget and resources agreed with the client. An external consultant, on the other hand is normally fulfilling a non-employee role that usually exists within the organization and is helping to bridge a gap caused by staffing shortages, skills and expertise. They are directed by the normal management structure of the organization. There is, however, a hybrid form where a consultant may be hired as an interim manager or executive, bringing a combination of specialist expertise to bear on a role that is temporarily vacant (usually at a senior level).
Though most of the back-office research and analysis occurs at the consultants' offices or home-offices, in the case of smaller consulting firms, consultants typically work at the site of the client for at least some of the time. By spending time at the client's organization, the consultant is able to observe work processes, interview workers, managers, executives, board members, or other individuals, and study how the organization operates.
The governing factor on where a consultant works tends to be the amount of interaction required with other employees of the client. If a management consultant is providing advice to a software firm that is struggling with employee morale, absenteeism and issues with managers and senior engineers leaving the firm, the consultant will probably spend a good deal of time at the client's office, interviewing staff, engineers, managers and executives, and observing work processes. On the other hand, a legal consultant asked to provide advice on a specific property law issue might only have a few meetings at the client's office, and conduct the majority of his work at the consultant's office and in legal libraries.