Facilitated Diffusion- molecules like glucose is to big that it cannot pass by regular diffusion; therefore, there are protein channels that allows them to pass.
A group of people trying to go from one side to another through a weak and really narrowed bridge. they need to use a bigger and stronger bridge to be able to pass through. all the people are in one side but they start to move to the other side one by one. those people feel to crowded in one side and they need more space, so therefore they move to the other side. they are moving from a high concentration to a low concentration.
In the picture below you can see people crossing a bridge from one side to the other.