Staphylococci and Streptococci are grouped as Gram-positive cocci. Staphylococci form clumps, whereas Streptococci grow in chains. They can be discriminated by catalase test because Staphylococci have the capability to produce catalase.
Both bacteria contains a rigid cell wall, which is made up of murin. The average diameter of a bacterium in both cocci and bacilli is around 0.5 µm. The main difference between cocci and bacilli is that cocci are spherical or oval-shaped bacteria whereas bacilli are rod-shaped bacteria.