What type of bacteria are spherical and can appear singly or in groups?

Cocci refers to spherical-shaped bacteria that can exist either as individual cells or in clusters. This group includes various types of bacteria, such as staphylococci, which form clusters, and streptococci, which appear in chains. The defining characteristic of cocci is their round shape, which differentiates them from other bacterial forms, such as bacilli, which are rod-shaped, and spirilla, which have a spiral shape. Understanding the morphology of bacteria, including cocci and their potential arrangements, is fundamental in microbiology and helps in identifying and treating infections.