Paper goods usually refers to items made of paper other than paper used for writing. They include plates, cups, napkins.
Paper goods are usually used once and then thrown out. They are not normally sturdy enough for washing and re-use. Since they are made of paper, they are generally biodegradable. However, sometimes they are coated with materials that make them less biodegradable. Also, sometimes the term is used more generally to refer to disposable items that may be made of other materials, like plastic.