Subjectivity is so pervasive to the human condition that it is difficult to say where this would not hold sway. We could say that subjectivity is the capacity to experience things in a personally specific manner, often so as not to be able to explain these to another in a manner that would be perceived in a compatible way by this other. The tendency to subjectivity could be said to be the principal obstacle to clear communication between people.
In popular parlance, subjectivity is often linked to emotional reaction. Subjectivity is however not the same thing as emotion. Subjectivity is the preference to rather consider one's favorite beliefs than the external world. Such a tendency is generally backed by a strong emotional attachment to these beliefs. Emotion in itself may serve seeing the world as it is, thus subjectivity is rather a misuse of emotion than its intrinsic attribute.
Subjectivity is opposed to consciousness in the sense that it arbitrarily confines itself inside one preferred manner of seeing. Subjectivity can become so habitual that the implicit restrictions imposed by it on itself disappear from its conscious reach. Subjectivity can to varying degrees confine itself in an invisible prison bounded by possibilities that are automatically shut out from consideration. Sometimes these possibilities are not shut out per se but are emotionally judged a priori unacceptable and thus never get deeper review.
Subjectivity is at the metaphysical level the placing of one's beliefs or conceptions, however these may have arisen, before any concern for how things may be in the outer world. Subjectivity is in a sense a statement to the effect of wishing to be separate from this outer world. This makes subjectivity an attribute of the service to self polarity.