Cell types: As you are aware of, the human body is composed of various kinds of cells such as muscle cells, nerve cells, and epithelia cells. Organisms like C. elegans are also composed of different cell types to form specialized functional organs.
A worm with different cell types color coded:
This was published upon the completion of C. elegans cell lineage (Sulston et al, 1983, P. 90). According to development, the figure runs from top down with different cell types developed from their own mother cells. (Click on the image to see its larger version)
A representation that maps all the cell types to color. The colors of the cell types in this image match the worm image shown above. (Click on the image to see its bigger version)