Interviews can take a variety of forms, some of which are: face-to-face interviews, telephonic interviews and there are group interviews. Having an interview is often the first stage of the selection process. Some companies do a telephonic interview first and then a face-to-face interview, which is then followed by psychometric testing. The bigger corporate sometimes require further interviews where the interviewers are the directors of the company as opposed to HR personnel. Sometimes there is just one interview and from that, the best candidate is selected.
If there are many applicants to get through, it is possible that individuals may have group interviews. Interviewers sometimes present the question to the whole group, so it is important to speak confidently and to not be intimidated by everyone else. Interviewers will some split the group into mini groups and will present them with a case study that has to be solved or require them to do a presentation on a certain topic.