How do cell walls differ from cell membranes?
In the most basic sense, they differ in that cell walls are more solid, and provide less room for movement. This is because cell walls are made of stiff polysaccharides (plants have cellulose , fungi have chitin , and bacteria have peptidoglycan ). On the other hand, our cell membranes are simply lipid bilayers, and are not really that rigid.
This is also the reason why plant stems are much more rigid than animal skin.
Hope that helped :)