To answer the question of what Astrology is. Using the very nomenclature of that symbology this may be answered by looking at the Astrological chart of an Astrology forum itself.
This chart contains elements which are common to other forums of a similar nature. This forum has recently been created and can be found here: http://s1.zetaboards.com/Astrology_Forum/index/
What is interesting here is the domination of this chart by both Mercury and Saturn held in mutual reception and dispositors of not only all planets, but of 9th house. This chart emphasises the 5th house through Ascendant ruler´s rulership of that house and Saturn´s position there. Though this has nothing to do with knowledge or pure astrology, and more to do with romantic ventures, gambling, ego and fun. Node in the 9th house seems to be another indication of the search for true knowledge.
Astrology within the chart:
Astrology is a system of symbols which clearly make up a certain form of philosophy. A philosophy in which knowledge is infinite as opposed to finite is indicated by the 9th house. Starlight Knight Forum has both Jupiter and Node in this placing with 9th ruler Saturn dispositing most of the chart including MC. Mercury is very important though, marking a mutual reception, between the higher knowledge of the 9th and the individual search for that knowledge and understanding through Mercury.
Astrology forum 2 (Astrodienst):
Once again the 9th house is the primary focus of its existence, with the 9th ruler Jupiter placed in domicile and pivoting the whole chart from the 5th house of ego. Saturn as dispositor of Aquarius seems to be highly accidentally dignified and in this case concerned with the self (5th house). The Sun in this chart rules the 1st and 2nd house, meaning that there is a financial incentive for this forum as a part of the Astrodienst site, and this is exalted, indicating that the success here is guaranteed without the need for the free service which it provides.
Astrology Forum 3 (Astrology Weekly):
Ruler of the 9th once again is highly important despite being in detriment. Sun as centre of a 3rd house stellium in Saturn´s intellectual sign in the house of communication and learning, house 3.
The Common Thread:
Different styles and different sets of interests are clearly marked by these forums. But the common thread of these all is an interest in the same subject, the same houses are marked with the same planets. The 9th house, Mercury and Saturn as well as the Sun and Aquarius.
Motivations and personalities always figure in anything created by someone. And in these charts it would be noteworthy to take heed of the fact that some connect the essence of the forum Ascendant ruler with ruler of the 5th house, with the 11th, with the 2nd or with the 3rd. An astrologer has a vision of creating a place in order to increase the trade of their site, and the 2nd house is obviously disposited as a result. Another may simply want to create a fun place for mutual interests, friendship and perhaps even romance, and those houses are emphasised in a likewise manner.
The essence though is an experience and a symbolism, a language which relates to the dual worlds about us. The parallels between the Earthly plane ruled by Saturn and the Heavenly plane of the 9th house.