Jyotish Spans the Lokas
Vedic astrology (Jyotish) deals with subtle energies that correspond to what are known as tattvas (elements) in the Hindu yoga tradition. Because of this, Jyotish has much to say about the many different planes of consciousness (lokas) that figure into what we call existence or nature. The most fundamental lokas relate to everyday experience (physical plane = natal chart), the occult worlds (astral plane = navamsha (D9) chart) and a level of psychic experience even deeper than the occult worlds (causal plane = bhamsha (D27) chart). These three planes are the most relevant levels for the vast majority of people, whether they live an ordinary life or aspire to become enlightened. For instance, a very famous prayer in Hinduism, called the Gayatri mantra, starts off with the words: "bhur, bhuva, svaha" which relate to these three planes. Thus, it invokes all the relevant dimensions of reality so that its prayer may have the greatest positive effect.
The Jyotish Star Map
In Hinduism, the lokas span even further out beyond these three levels all the way up to the greatest heavens, where the mightiest saints and sages and the purest gods and goddesses live. Jyotish, however, also addresses other realms: ones that go all the way down to the darkest and most infernal hells. In total, seven lokas are referenced (from our world of ordinary experience up through the highest heavens) and a supplemental scheme is applied to classify the hell regions (all strata below the earth plane).
While Vedic astrology has charts and tools to understand all these levels of experience, the most important charts it works with are the natal chart and navamsha chart. With just these two and a few extra trinkets, you have a brilliant model for your life—what you should be doing, how you can tell if you are on track, what's going on right now, why things happened the way they did, what opportunities you have access to ... and, most importantly, clear guidelines on how you should live your life, regardless of the path you choose to follow (wealth, happiness, virtue, spirituality).
Here's a look at some of the details involved. You can click on each slide to get a larger, clearer view: