What is concentration gradient? How does it affect diffusion?

Are you on Chapter 3 in the BSCS Biology A Molecular approach??????? Are you doing the Check and Challenges????????? 'Cause I am right now and they suck. Stupid Honors Bio. Are you a freshman?????? By the way I wrote when there is a difference in concentration of molecules across a distance that is a concentration gradient. Diffusion and concentration gradient are related because molecules diffuse from regions of higher concentration to regions of lower concentration, they are described as moving down their concentration gradient.