In an interviewer-led case interview, the interviewer leads through the conversation. This means that the interviewer asks specific questions and also controls the time you have to analyze and answer different questions and therefore the depth of your analysis. In contrast, the candidate-led style (which is more common) is about you taking the initiative as a candidate. The initial problem is given to you by your interviewer. Afterwards, you have the freedom to structure the case according to your ideas and to ask questions proactively in order to find a solution to the problem.