A zodiac sign is a section of space that is related to constellations that exist along the ecliptic, the orbital path of the planets around the sun

The Zodiac 

The zodiac as we know it refers to a 12 fold division of the sky based on certain astronomical phenomena and / or groups of stars. The ancient seers of India realized the cosmic energy in certain star groups and constructed the 12 fold zodiac from those star groups (as opposed to a Tropical/Earth Based Zodiac). This stellar / constellation based Zodiac was the basis of India's most sacred texts, the Vedas.

* Below material was originally published by David Frawley in a commentary on the Astronomy of the Vedas.

Most of the astronomical information occurs in his (Dirghatamas) famous Asya Vamasya Hymn I.164. Much of this hymn can be understood as a description of the zodiac. It begins:

1. “Seven yoke the chariot that has a single wheel (chakra). One horse that has seven names carries it. The wheel has three naves, is undecaying and never overcome, where all these beings are placed.”

Commentary:
The zodiac is the single wheeled-chariot or circle yoked by the seven planets which are all forms of the Sun or sunlight. It is the wheel of time on which all beings are placed. The Vedic horse (ashva) is symbolic of energy or propulsive force.

2. “This chariot which the seven have mounted has seven wheels (chakras) and is carried by seven horses. The seven sisters sing forth together, where are hidden the seven names of the cows.”

Commentary:

The seven planets create their seven rotations or seven wheels. Each has its horse, its energy or velocity. Each has its feminine power or sister, its power of expression. It carries its own hidden name or secret knowledge (symbolically cows or rays). This refers to the astrological influences of the planets.

11. “The wheel of law with twelve spokes does not decay as it revolves around heaven. Oh Fire, here your 720 sons abide.”

The circle of the zodiac has twelve signs. It has 720 half degrees or twins, (Karanas) making 360 total.

Shatapatha Brahmana

“The Father with five feet and twelve forms, they say, dwells in the higher half of heaven full of waters. Others say that he is the clearseeing one who dwells below in a sevenfold wheel that has six spokes.” 

The five feet of the father or the Sun are the five planets or the five elements that these often refer to (to which Vedic thought associates the five sense organs and five motor organs in the human body). His twelve forms are the twelve signs. The Sun in the higher half of heaven with the waters is the signs Leo with Cancer (ruled by the Moon), with the other five planets being the five feet, each ruling two signs.

The sevenfold wheel is the zodiac moved by the seven planets. The six spokes are the six

double signs through which the planets travel.

The same verse occurs in the Prashna Upanishad

I.11 as a symbol for the year.

14. “The undecaying wheel (circle) together with its felly (circumference), ten yoked to the upward extension carry it. The eye of the Sun moves encompassing the region. In it are placed all beings.”

This may again refer to the ten signs ruled by the five planets, with each planet ruling two signs. The eye of the Sun may be the sign Leo through which the solar influence pervades the zodiac or just the Sun itself. The upward extension may be the polar region.

15. “Of those that are born together, the seventh is born alone. The six are twins (yama), Divine born rishis. The wishes that they grant are apportioned according to their nature. Diversely made for their ordainer, they move in different forms.”

The six born together are twins of the twelve signs, two of which are ruled by one planet (considering the Sun and Moon as a single planetary influence). The seventh that is singly born is the single light that illumines all the planets. 

Zodiac Signs

Below are the Verses on Astrology signs from Briha Parashara Hora Sastra

4-4½. Limbs of Kaal Purush. Kaal Purush (or Time personified) has his limbs, as under with reference to the 12 Rashis, respectively: Head, face, arms, heart, stomach, hip, space below navel, privities, thighs, knees, ankles and feet.

5-5½. Classification of Rashis. Movable, Fixed and Dual are the names given to the 12 Rashis in order. These are again known, as malefic and benefic, successively. Similarly are male and female. 

PLANETS

SIGNS

A Few Facts About the Sun, Moon and Astrology Signs:

There are 12 Astrology Signs, each of 30 Degrees. Each degree of an astrology sign actually relates to how far the Earth moves around the Sun each day. Thirty days approximate the Lunar cycle (15 days of waxing and waning cycles).

We call this a month. (“Month” from “Moon).

Thus the astrology signs approximate how far the Earth travels around the Sun each lunar cycle.

In truth, as we know, the Sun just appears to move in the Sky through the Signs, but it is actually the Earth moving around the Sun that creates the appearance of the Sun moving.

Every 30 days (approximately) the Sun enters a new sign. Western astrology is based on this principle. Your Western astrology sign is based on which sign the Sun was in when you were born (according to the Western Astrology Zodiac). (12x30=360 The approximate length of the year)

The astrology signs are not connected directly to the Earth, Sun and Moon in real time. They break the sky up into different sections and relate those sections to certain universal concepts related to the Stars (the siblings of our Sun).

There is a beautiful symmetry to the astrology signs. Before the Sun, Moon and Earth were supporting life the Stars were there. They form the limbs of the Kala Purusha (The being in time placed on the wheel of Karma).