Shredded and Grated are two words with almost the same meaning. Shredded and grated are used as the past tense of both 'shred' and 'grate,' but they also mean to cut or torn something into narrow pieces using a shredder or to shred things by rubbing across a grater. Shredded material is one cut into narrow pieces using a machine that tears up objects into smaller pieces. Examples of documents that can be shredded are foodstuffs.
Grated materials, on the other hand, are materials that have been grated using the grater to turn an object into tiny fragments, so much that it is almost in powdered form. Most times, we confuse shredding with grating. The difference between a grated material and a shredded material is like content they produced. Grated materials are turned into narrow pieces, while grated materials are turned almost to powdered material.