The document discusses the differences between sensation and perception. Sensation is defined as the passive process of bringing external stimuli into the body and brain through the senses. Perception is the active process of selecting, organizing, and interpreting sensory information in the brain to give it meaning. Sensation involves sensory receptors detecting stimuli and transmitting neural signals, while perception occurs as the brain organizes and interprets those signals. The key differences are that sensation is passive intake of raw stimuli, while perception is the active interpretation and understanding of sensory information.