The 3 engagement "indicators" are discrete factors from the 12 engagement "drivers," so each of the 15 factors has its own set of questions. The drivers reflect employee perceptions regarding job features, supervisory behaviors, or organization practices that have been shown to drive engagement, which is indicated by overall job satisfaction, organizational commitment, and sense of alignment.
By including both indicators and drivers in the Employee Engagement Report, you can get a 'pulse check' on how employees are feeling and their general attitudes and sentiment toward the organization (i.e., "indicators"), as well as insight into the specific levers that are likely driving these feelings and attitudes (i.e., "drivers").