Answer:
Simple diffusion, facilitated diffusion, and active transport are three types of cellular transport that occur across cell membranes.
Simple diffusion is a type of transport in which a substance moves spontaneously from an area of high concentration to an area of low concentration.
Facilitated diffusion is a type of transport in which a substance moves from an area of high concentration to an area of low concentration with the aid of special transport proteins.
Active transport is a type of transport in which a substance moves from an area of low concentration to an area of high concentration through the use of cellular energy, or ATP
Resources from Practice Session Cellular Transport & Homeostasis Study Island