Usually there is two to three phases of the interview sometimes even more; an initial interview w/ the recruiter so it is just an agent that comes to have a first glance meeting with you, to have introductions done, so you could introdude yourself and so that the agent can also introduce the company and what it does for you. Afterwards you would have a an interview with the person in charge of the domain that you are looking for or interested in working in, that one goes a lot more in details to understand better the overview of your career choice and also your hard skills related to the job itself. Then if the process goes well and it seems that you are a good fit, you would need to have a furthur interview with the client if you are interested in working for certain clients and not the consulting company itself directly; That is more of an introduction with the client to know and understand why you are a good fit and for the client to check all and all if you have what it takes for the job and for you to know more in details what is best for you. After that you will know axatcly what the next step is either get hired by both companies and you will work directly with the client you have found OR you may also just get hired by the consulting company and they will work dirctly on finding a suitable job offer for you.