This website uses "the collective" to essentially mean society at large, a religious community, a local community, etc. Depending on the context, it might also mean your group of friends, or even the infamous "they" that we all refer to. It could be a communal "we" that you feel a part of. It refers to the collective will, the "hive mind" or group norms. It might refer to a group of people as distinct and united in some way. The collective is a unified group entity that is "greater than the sum of its parts."
Astrologically, the Collective is most often reflected in Aquarius and the 11th House through groups, friends, communities, associations and the masses.
At a certain level, the family is another type of Collective (Cancer, 4th House), as well as the local community and neighbourhood (Gemini, 3rd House), or conventional, structured society with its rules, laws and expectations (Capricorn, 10th House).
