HELP What is the three catergories for eptihelial tissues?

Epithelial tissues are generally classified by the morphology of their cells, and the number of layers they are composed of] Epithelial tissue that is only one cell thick is known as simple epithelium If it is two or more cells thick, it is known as stratified epithelium. However, when taller simple epithelial cells (see columnar, below) are viewed in cross section with several nuclei appearing at different heights, they can be confused with stratified epithelia. This kind of epithelium is therefore described as "pseudostratified" epithelium.