Spinal tracts are basically groups of nerves which are named based on the type of information that they send as well as the origin and destination of signals. There are two main types: Ascending tracts, which include Spinothalamic, Spinocerebellar, Fasciculus Gracilis and Fasciculus Cuneatus; and Descending tract, which is the Corticospinal tract.
Ascending Tracts
The Spinothalamic tracts carry conscious pain, temperature, crude touch, and pressure. The Spinocerebellar tract carries unconscious proprioception to the cerebellum which is responsible for muscle coordination. What is proprioception you ask? Close your eyes and hold your hands straight out in front of you. How do you know your hands are straight out in front of you? The nerves in your arms send a signal to your brain so that you feel where your hands are at. That's proprioception. The Fasciculus Gracilis and Fasciculus Cuneatus tracts carry discriminative touch (the gracilis) and conscious proprioception (the cuneatus). Discriminative touch allows you to specifically localize the location whereas crude touch does not.
Descending Tracts
The Corticospinal Tract, or Pyramidal Tract, originates in the cerebral cortex where voluntary motor control is localized. There are two branches, the lateral and the anterior. The lateral crosses in the medulla in an area known due to its appearance as the pyramids. The anterior does not cross. These fibers are called "upper motor neurons" and they synapse with "lower" motor neurons in the cord which lead to the skeletal muscles.
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