NLP stands for Neuro-linguistic programming and refers to the preferences we all have for communicating, learning and dealing with the external world.
NLP is one of the recent developments in psychology that has a practical application in the classroom. It focuses on the different ways that people organise the world around them on a cognitive level. It also reflects the way people absorb new information into what they already know. It also has relevance to the way people communicate with others, like to be communicated with and how they react to other people's communication.
Neuro refers to how we experience the world through our five senses and how we represent the external world in our minds. We all have preferences for visual, auditory, kinesthetic, olfactory and gustatory modes (the last two are less common). A liking for more than one mode is also possible.
Linguistic refers to how we express these preferences. To show understanding we might say "I see what you mean", (visual) "I hear you" (auditory), "I get it" (kinesthetic).
Programming refers to learning how to interact in new ways in order to achieve our potential.
If you know your students' preferred learning and communicating styles, you can increase learning potential in the classroom. Start by knowing your own style and be aware of the fact that teachers usually teach using their own preferred style. This is hardly surprising as it represents our own zones of comfort.
For further information, you can look at "In Your Own Hands" by Jane Revell and Susan Norman.