Some companies have computers that contain all the information. Then interviewers can run a program that selects job seekers who qualify for the job. Not all interviewers use computers though. Some rely on their memory and sense of who will fit well in a job. The duties of employment interviewers differ depending on whether they are working for a business or the government.
Employment agencies are businesses that are paid when they find an employee to fill a position.
Interviewers at these agencies are often called employment counselors. Counselors generally work with people who have many skills. Often the people who come to these employment agencies are new to town and do not have connections. Counselors provide job seekers with the background on the company with which an interview is scheduled. They also offer tips on personal appearance and interviewing.