Can you provide examples of both gram positive and gram negative bacteria in the context of bacterial classification?

Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, retaining the crystal violet stain in the Gram staining process. Examples include Staphylococcus aureus and Streptococcus pneumoniae. Gram-negative bacteria have a thinner layer of peptidoglycan and an outer membrane, causing them to lose the crystal violet stain. Examples include Escherichia coli and Pseudomonas aeruginosa.