What is facilitated diffusion?
Facilitated diffusion is diffusion through a membrane which occurs through a transport (or channel) protein.
Some particles/molecules are not able to pass directly through the membrane, so they need to pass through special transport proteins which act like doorways.
Facilitated diffusion gets its because to facilitate means to help.
Here is a video to help visualize how the process of facilitated diffusion occurs.
Hope this helps!