It is an index of how much vitality, strength and energy you have. A life line running close to the thumb indicates a person of low vitality, sometimes found in the hands of people who suffer chronic fatigue syndrom.
A life line that runs a wide curve shows a person with lots of vitality, get up and go. If the head line is stronger than the life line it shows a person who is more mentally than physically active.
A chained life line indicates a delicate health. Little lines rising indicate an active personality.
Outward swinging lines indicate a love of travel. Most of the small lines on the life line refer to particular events at certain times of your life.
A branch leading to the Jupiter mount is a sign of academic achievment. A branch that leads to the Saturn mount indicates a successful property transaction.
A branch towards the Appollo mount indicates monetary gain. A branch towards the Mercury mount indicates business success.