Both staphylococci and streptococci grow in arrangements, but each arrangement differs. Staphylococci grow in a grape like clusters, while streptococci form a chain of round cells. That would be a useful difference to locate them in a petri dish. On the other hand, they greatly differ in their habitat. Staphylococci is found mainly in the skin, while streptococci has preference for the respiratory tract. Common species from staphylococci are: Staphylococcus aureus, S. epidermis, S. hominis, etc. While common sp form streptococci are: Streptococcus pyrogenes, S. bovis, S. pneumoniae, etc.