Question

what exactly is diffusion and what does it have to do with a cell?

Answer 1

Diffusion is the movement of particles from an area of high concentration to an area of low concentration. It is implicit that there needs to be some means to divide areas into high and low concentrations. This is where the cell membrane comes in since it is an object that separates the cell from its environment. Also, the cell membrane is selectively permeable which means that it allows some particles (usually smaller and unchanged ones) to pass through it more easily than others, this will create gradients between the cell and its environment where one has a higher concentration of certain particles than the other.

Answer 2

Wow! That was truly helpful! Thankyou! :D