Chromatin - DNA that is loosely coiled around a protein. When the cell in NOT dividing, DNA is in this form but cannot be seen in most light microscopes.
Chromosome - chromatin is condensed into chromosomes when the cell divides (mitosis/ meiosis). Humans have 23 pairs of chromosomes which contain all of your DNA. These are visible in a light microscope.
Has the genetic code that directs what proteins get made