It's a tool for seeing yourself with clarity so that you can make intelligent choices about your life. See my page on Consultations for more information. Astrologers can focus on different areas based on their inclinations and their clients' needs. Some astrologers are rooted in a spiritual approach and may discuss past lives, karma and so forth. Others are psychologically oriented and will investigate patterns developed during childhood and how to change them.
Practical considerations regarding money, career and health are other common areas of inquiry.
Most astrologers have can move among these different areas, but have their basic approach. It's appropriate to ask questions before making an appointment for a consultation. Most of my clients see me at least once a year. Some call when they have particular issues that come up. Others like an update more frequently.