Recruiter or Recruitment, which means the solicitation of individuals to fill jobs or positions or roles within any group, such as an organization or corporation or sports team, where IT Recruiters are specifically to fill the positions in IT companies.

Recruiters can be divided into two groups.

• Those working internally for the welfare of one organization called HR.
  
• Those working for multiple clients in a third-party, sometimes called Headhunters or Third Party Recruiters or a professional recruiter like Consultancy business.
  

Third Party Recruiters or Headhunters called as an IT Recruiters in Organizations

A Third Party Recruiter acts as an independent contact between their client companies and the candidates they recruit for a position. They can specialize in client relationships only, and in finding candidates. Most recruiters tend to specialize in permanent or full-time, direct hire positions or contract positions, but occasionally in both.

Executive search agents/professionals who typically have a wide range of personal contacts within the area in question, a detailed specific knowledge of said area, and typically operate at the most senior level. Executive search professionals are also involved throughout more of the hiring process, conducting detailed interviews as well as only presenting candidates to clients where they feel the candidate in question will fit into the employment culture of the client. Executive search agencies typically have long-lasting relationships with clients spanning many years, and in such cases the suitability of candidates is paramount. It is also important that such agencies operate with a high level of professionalism.

Specialization

Headhunters tend to either be generalists or specialists in a particular niche, with some recruiting firms also specializing in a geographical region as small as a city, and others recruiting worldwide. Niche headhunters may specialize in a specific industry or type of employee, such as medical specialists, information-technology professionals, senior-level executives, or sales professionals.

Hope it gives you the basic idea about the recruiters and recruitment