Here, your interviewer wants to know about how you perceive the work you perform, and how you prioritize the importance of your responsibilities. This question is particularly important to an employer when you are interviewing to do the same or similar work as you did for another company, but is also applicable when you apply for a new position so the employer can see that you have a clear picture of what must be done. Describe the functions and actions that require the most preparation, planning, cooperation, concentration, sensitivity, etc. and the ones that are most important to the successful completion of your tasks. Ultimately, expressing that you understand what is most critical in the eyes of the employer will be very important in answering this question with the most impact.