The Elements
There are four groups of elements: Fire, Earth, Air, and Water. Each element carries with it characteristics that apply to the three signs of that element.
Fire Signs
The Fire Signs are Aries, Leo and Sagittarius. People with lots of fire in their chart are very active and involved and "can do" all kinds of things. Those with little fire can't get started and may need someone to light a fire under them.
If you have many planets in Fire signs in your natal chart, your positivism lets you get right to the point, and you have little patience with those who shilly-shally. You've plenty of enthusiasm and warm up to things and people quickly. You have an inner self-confidence which burns with its own light.
If you have few planets in Fire signs in your natal chart, your inner self-confidence may be lacking, and you could try to overcome this by defensive aggressiveness. You probably wish you had more of the self-assurance your fiery acquaintances have.
The Elements