Which spinal cord tract carries voluntary motor commands from the left cerebral cortex to the muscles on the left side of the trunk and the proximal parts of the left limbs

The basic repeating unit of nucleic acids are known as nucleotides. a nucleotide consists of three distinct chemical groups.

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it