The employer must know the company and work environment well enough to give you a good idea of what it is like to work there. Your roles change during the process. In the interviews, you are selling yourself to the employers. This is why you should defer discussion of salary and benefits until you are offered the position. It is at this point that you can actually negotiate from a position of strength.
Interviews come in all lengths of time.
They can range from fifteen minutes to a couple of hours. The most common for you will probably be 30 minute interviews. You may also have several of these interviews in a row, within one day of interviewing. In the screening interview, the employer might go into detail about their organization. FIVE minutes - You ask questions.