NLP stands for Neuro Linguistic Programming. Neuro refers to our neurology or nervous system which includes our brain, mind and all of the nerves and neurons that make up the nervous system. Linguistic refers to the language of the nervous system, through which we experience the world.
This being our visual senses (sight), auditory (hearing), kinaesthetic or feelings, smells, tastes and what we say when we talk to ourselves – our internal dialog. Programming refers to the programs or sequences of internal representations that we run in our neurology.
NLP is really the Art and Science of understanding this. It is often described as an attitude and a methodology that leaves behind a trail of techniques. The attitude being one of curiosity, experimentation and of acting as-if. The methodology is the art of modelling this, and the trail of techniques are the models and strategies that are the result.
See also the Law of Consequences, Law of Equivalences, Law of Value, Law of Coherence, Law of Requisite Variety