Gram-positive cocci are a type of bacteria that appear spherical under a microscope and retain a purple color when subjected to the Gram stain procedure. This characteristic is due to their thick peptidoglycan cell wall, which traps the dye. Common examples include Staphylococcus and Streptococcus species. These bacteria can be found in various environments, including on human skin and in the respiratory tract. While some Gram-positive cocci are harmless or beneficial, others can cause infections, such as pneumonia or skin infections. Understanding their classification helps in diagnosing and treating bacterial infections effectively.