At a minimum the interviewer is looking to discover the following:
WHAT does the candidate want to do? The interviewer wants to be sure that you will be happy performing the tasks required to complete the job properly. Few employers can afford to let new employees “try out” for jobs until they find one they like. Candidates need to be focused on what they want to do now and in the very near future. This job cannot be a stopping off point for the candidate.
CAN the candidate do what they say they can? Interviewers try to discover how closely your knowledge, skills and abilities match those required for the job.
WILL the candidate actually do the job? It is every employer’s nightmare that they will hire someone who simply will not do the job. You must assure the interviewer that you will show up for work, will be on time and put forth your best effort into the task at hand. The interviewer is also concerned about your personality. Will you be easy to work with? Will you cause morale problems among the other employees?