The Elements in Astrology Help Us Categorize the Signs
There are 12 signs and 4 elements: FIRE, EARTH, AIR & WATER. Each element has similar traits and characteristics. In general, we tend to have ease as well as relate better with people who have complimentary elements to us. In the above color coded picture, you can see which signs are in each element.
From a relationship standpoint, we seem to attract to people who have elements that we’re lacking. For more on the topic of attraction check out: The Elemental Shakeup of Love and Longing