The Eskimos, it is often said, have twenty different words for snow. Snow being such an intimate part of their lives, they are much more aware of its many variations In Sanskrit, the language of ancient Indian philosophy, which focused on the exploration of the human mind, there are probably as many words for consciousness. In English, a language that did not evolve with a keen concern for inner states, we use the word consciousness to mean many different things.
An awake person is consciousness; someone asleep is not. Or, a person could be awake, but so absorbed in their thoughts that they have little consciousness of the world around. We say an action is conscious when it is deliberate. We talk of political, social or ecological consciousness. Some say that human beings are conscious while other creatures are not, meaning that human beings think and are self-aware. Or (and this is the sense in which I shall mainly be using the word) we use consciousness to refer to the interior world in which all experience takes place. Whatever it is that we are aware of -- our perceptions, our thoughts, our feelings, our memories, our dreams -- they all are subjective experiences of one kind or another. They all occur within the realm of consciousness.