Nerve pathway of a simple reflex. When the sensory nerve ending is stimulated, a nerve impulse travels along a sensory (afferent) neuron to the spinal cord. Here an association neuron transfers the impulse to a motor (efferent) neuron.
Deeds are instruments used to record ownership interests. When you purchase or otherwise come into ownership of real estate such as a house, you gain an ownership interest in it. Ownership interests in real estate can be solely held or divided among several people.
In the commercial setting, one can often have the equivalent of an ownership interest without actually owning a blasted part of a property. That is because people are free to engage in lawful activities on a property and can, in effect, do anything they want.