What is the difference between starch and fibers. And what is cellulose and hemicellulose. Starch we can find in potatoes and rice. And plant makes the structure of plant cell wall.

Starch is a complex carb, ( i.e. boiled rice, pasta, wheat corn and potatoes.)
Fiber is another term for carbs that are indigestable, it also aids in digestion. i.e. beans, peas, oatbran, fresh fruit and veggies).
Cellulose is an organic compound the primary structure of green plants.
Hemicellulose is more complex than a sugar and less complex than cellulose, this is present in almost all plant cell walls along with cellulose. Hope this helps a little