Simple squamous epithelium consists of thin, flat cells that allow for rapid diffusion of gases and nutrients. It is commonly found in the alveoli of the lungs.

Simple cuboidal epithelium is made up of cube-shaped cells that function in secretion and absorption. It is often found in the kidney tubules.

Stratified squamous epithelium consists of multiple layers of flat cells that provide protection against friction and abrasion. It is commonly found in the epidermis of the skin.