The Lunar Nodes are where the Moon's path around the Earth intersects the apparent path of the Sun through the zodiac.
The North Node generally symbolizes lessons in life and where you need to grow. It may also represent where you meet people who can help you along the way.
The South Node generally represents past patterns and what you need to let go of. It can also be where you need to move a primary focus into the background to make room for new challenges.