shredder

An shredder is a machine that destroys or tears up materials like paper, plastic, or even metal.

You might see a shredder at work or school being used to dispose of confidential documents like old bills or financial reports. It's also common for offices to have a shredder as part of their security measures to protect sensitive information from falling into the wrong hands. Sometimes people use household shredders to destroy personal papers, like receipts or old credit card offers, that they don't need anymore.