There are four major palm lines and each represents something. The lines on you dominant hand and your passive hand mean different things from one another as well. The passive hand idnicates inherited traits while the dominant hand indicates traits that are changed by life events.
The four major lines include the heart line, the head line, the life line, and the fate line. There are other lines as well that are not considered major lines these include the health line, the fame line, the marriage line, money lines, and travel lines. Each line tells you something about someone's life past, present, or future.