The key to understanding Noddings' ethics of care is to understand her notion of caring and ethical caring in particular.
Noddings believes that it would be a mistake to try to provide a systematic examination of the requirements for caring; nevertheless, she does suggest three requirements for caring (Caring 1984, 11-12). She argues that the carer (one-caring) must exhibit engrossment and motivational displacement, and the person who is cared for (cared-for) must respond in some way to the caring (1984, 69). Noddings' term engrossment refers to thinking about someone in order to gain a greater understanding of him or her. Engrossment is necessary for caring because an individual's personal and physical situation must be understood before the one-caring can determine the appropriateness of any action. 'Engrossment' need not entail, as the term seems to suggest, a deep fixation on the other. It requires only the attention needed to some to understand the position of the other. Engrossment could not on its own constitute caring; someone could have a deep understanding of another person, yet act against that person's interests. Motivational displacement prevents this from occurring. Motivational displacement occurs when the one-caring's behaviour is largely determined by the needs of the person for whom she is caring. On its own, motivational displacement would also be insufficient for ethical caring. For example, someone who acted primarily from a desire to accomplish something for another person, but failed to think carefully enough about that other person's needs (failed to be correctly engrossed in the other), would fail to care. Finally, Noddings believes that caring requires some form of recognition from the cared-for that the one-caring is, in fact, caring. When there is a recognition of and response to the caring by the person cared for, Noddings describes the caring as "completed in the other" (1984, 4).
Nel Noddings draws an important distinction between natural caring and ethical caring (1984, 81-83). Noddings distinguishes between acting because "I want" and acting because "I must". When I care for someone because "I want" to care, say I hug a friend who needs hugging in an act of love, Noddings claims that I am engaged in natural caring. When I care for someone because "I must" care, say I hug an acquaintance who needs hugging in spite of my desire to escape that person's pain, according to Noddings, I am engaged in ethical caring. Ethical caring occurs when a person acts caringly out of a belief that caring is the appropriate way of relating to people. When someone acts in a caring way because that person naturally cares for another, the caring is not ethical caring (1984, 79-80). Noddings' claims that ethical caring is based on, and so dependent on, natural caring (1984, 83, 206 fn 4). It is through experiencing others caring for them and naturally caring for others that people build what is called an "ethical ideal", an image of the kind of person they want to be.
Noddings describes wrong actions in terms of "a diminishment of the ethical ideal" and "evil". A person's ethical ideal is diminished when she either chooses or is forced to act in a way that rejects her internal call to care. In effect, her image of the best person it is possible for her to be is altered in a way that lowers her ideal. According to Noddings, people and organizations can deliberately or carelessly contribute to the diminishment of other's ethical ideals. They may do this by teaching people not to care, or by placing them in conditions that prevent them from being able to care (1984, 116-119). A person is evil if, in spite of her ability to do otherwise, she either fails to personally care for someone, or prevents others from caring. Noddings writes, "[when] one intentionally rejects the impulse to care and deliberately turns her back on the ethical, she is evil, and this evil cannot be redeemed" (1984, 115).
This is referred to as "obligation". "There are moments for all of us when we care quite naturally. We just do care; no ethical effort is required. 'Want' and 'ought' are indistinguishable in such cases." I have the ability to "abstain from action if I [so] believe that anything I might do would tend to work against the best interests of the cared-for." According to Noddings we are obligated to pursue the "musts".