Ehm, the name says it. It's the nerves that are all around your body and carry sensory information toward the central nervous system. I'll cite Wikipedia for convenience:
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A sensory nerve, also called an afferent nerve, is a nerve that carries sensoryinformation toward the central nervous system (CNS). It is a cable-like bundle of the afferent nerve fibers coming from sensory receptors in the peripheral nervoussystem (PNS).