The first photo shows a ciliated columnar epithelium that is most often found in the respiratory tract, such as the trachea. Its function is to propel mucous and move certain substances.

The second photo presents a simple cuboidal epithelium that is often seen in salivary and secretory glands which secrete mucous or serous fluid.

The third photo presents stratified squamous epithelium, often seen in the lining of our mouth. Primarily, it provides protection to specific parts of the body.