Four part model
The four part model of Nonviolent Communication is sometimes referred to as "OFNR" because the four parts are called Observations, Feelings, Needs and Requests.
The Observation(s) of concrete facts of a situation, free of judgement, guilt, blame or shame.
The Feeling(s) stimulated by the observation
The Need(s) that caused the feeling
A specific Request that is positive, concrete and can be done right now to serve the Need(s) discovered. An NVC Request can often easily be distinguished from a demand by what comes up if the answer is "No."
There is an out, in, out pattern to the model - the observation is something concrete and specific out in the world, the feeling and need help you go as deep as possible with what's alive in you and/or others, and the request is about manifesting as specifically as possible out in the world again.
There may be similarity between OFNR and "Active Listening" at first glance. However, the OFNR approach of NVC might be considered Reframing of language rather than "Paraphrasing." This is because NVC translates thoughts, judgements and some linguistic elements of dialog into Feelings and Needs. NVC also includes the Observation which helps to distinguish facts from interpretations of them, and the Request which tends to move the dialog closer to discovering and sharing appreciation of the Needs underlying all human feelings and behavior.
(this could obviously use a lot of expanding)
For an alternate taxonomy of needs, see the following links to the work of the Chilean economist Manfred Max-Neef: