Once your cell has gotten everything where it needs to go, how can it actually divide? Just as fences separate neighbors, why not use the cell wall to build a septum (“fence”) between the two daughters? That’s what this Staphylococcus aureus cell is doing, using its cell wall to begin cytokinesis–the physical division of the cytoplasm. In monoderm bacteria like this, with a thick cell wall, the septum is easy to see.
Staphylococcus aureus gets its name from the clusters of cells produced by repeated rounds of division, resembling grapes (or “staphyli” in Greek).