Pretty much any spirit, creature of folklore, creature of myth, etc. that you have heard of is an astral entity.
That being said, it should also be considered that there are also constructs that exist and appear as astral spirits. These are thoughtforms created by subconscious and conscious will and energy. Not necessarily the same as a "true" spirit, that is an entity created or formed outside of these psychological influences.
Thus most of the spirit guides, totem spirits, guardian angels, succubi/inccubi and so forth that people speak of are more the manifestation of their subconscious than a separate individual spirit. If the lore regarding such is examined carefully, it can be seen that most of it speaks of such assistance and guidance coming from within, and being born of intuition and enlightenment.
As for the individual spirits, for lack of better term, that are created and which function independently, these are often divided loosely into "low" and "high" spirits.
Low spirits tend to be those of a negative, or base energy. They are most frequently drive by base need or urge. They may also not be able to feel or comprehend complex emotion. Often this results in them being somewhat jealous of more complex emotion and needs. As a result, these spirits are often the one that bother people as they thrive on fear, anger, and other such base responses that they can trigger - feeding off of it, for lack of better terminology, and getting a "taste" of what it is to actually feel.
High spirits tend to be more complex. While often more positive, their complexity does not mean that they are necessarily good or evil. The greatest, to my experience, are not much of either and tend to remain aloof from such concerns. They are capable of a wide range of emotion, but the greatest among them are rarely driven by it. Indeed, the most potent of spirits are rarely influenced by emotion, viewing it more as another thing to perceive than anything that necessarily drives them to any course of action. This doesn't mean they are cold, robotic, and unfeeling. It merely means that they are atypically compelled through emotional triggers, or rash action.
As for the individual spirits descriptions, names, etc., well... They vary wildly. Each culture has its own perception of the vast array of such spirits, and each individual can potentially perceive each such spirit in their own way.