There are majorly three types of recruiters: retained, contingent and corporate.
Retained: This kind of recruiters have an excellent understanding about the employer. They receive fees for searching the candidate, they keep on submitting the candidate resumes until the employer closes that position.
Contingent: They do not get any retained fees, but they work on assignment basis. They receive their fees only when the candidates are hired. They work in the middle management.
Corporate: This category of recruiters is considered as employees of the corporation. Sometimes they search for all staff opening or they may be assigned for specific areas for e.g. professional and technical .They work under the direction of the Human Resource department. Corporate recruiters sometimes engage in the service of third party recruiter to locate candidates.