The zodiac is a circle of twelve signs called rasis. Each sign has an element — fire, earth, air or water — a modality — cardinal, fixed or mutable — and a ruling planet. The signs describe how a planet behaves, while the houses show where that behaviour appears in life.
Aries begins the cycle with initiative and courage. Taurus stabilises and values comfort. Gemini communicates and connects. Cancer nurtures and protects. Leo creates and leads. Virgo serves and refines. Libra harmonises and relates. Scorpio transforms and investigates. Sagittarius explores and teaches. Capricorn builds and perseveres. Aquarius innovates and supports groups. Pisces dissolves boundaries and connects with the unseen.
Your rising sign, or lagna, sets the starting point of the chart. The other signs then fall into the twelve houses in order. A planet in its own sign is strong; a planet in a friendly sign is comfortable; a planet in a debilitated sign must work harder to express its nature.
Understanding the rasis gives colour and texture to the planets in a chart.