Cracker crumbs can be sweet or savory. The crumbs can be purchased packaged or made yourself. The savory crumbs are used for topping casseroles and baked vegetables, or for breading meats or fish. You can make your own by putting saltine crackers in a heavy plastic bag and rolling them with a rolling pin OR place crackers in a food processor and process until crumbly. While saltine crackers are commonly used you can use any type of commercially prepared cracker.
Other non-savory crumbs include graham cracker crumbs, vanilla wafer and chocolate wafer crumbs.