Fixed Signs:
Taurus, Leo, Scorpio, Aquarius. People with a heavy emphasis in fixed signs hang onto and preserve life. They are at the center of things and are hard to budge. Folks with few planets in fixed signs may have trouble persevering and lack stick-to-it-ive-ness.

Modalities:
Another popular way of grouping the zodiac signs is by cardinal, fixed, and mutable.

Mutable Signs:
Gemini, Virgo, Sagittarius, Pisces. People with a heavy emphasis in mutable signs are on the move and transformative. They communicate and assist things to change. Folks with few planets in mutable signs may have trouble adapting or being flexible.

Water Signs:
Cancer, Scorpio, Pisces. People with lots of water are very feeling and "sense"-ative. Those with little water can't get a feel for things; they run cool.