A sticker is a type of label: a piece of printed paper, plastic, vinyl, or other material with pressure sensitive adhesive on one side. They can be used for decoration or for functional purposes, depending on the situation.
Stickers can come in many different shapes and sizes and also vary widely in color and design. They are often adhered to items such as lunchboxes, paper, lockers, notebooks, walls, cars, windows, and so on. Temporary name tags for example are frequently stickers.
Stickers are very widely used when an object requires identification with a word or idea. Brand stickers may be attached to products to label these products as coming from a certain company. They may also be used to describe characteristics of the products that would not be obvious from simple examination, or to clarify either a printing error or change in the product of some kind, such as the country of origination, shift in a product's ingredients, a shelf life date, or copyright notice, without having to scrap pre-existing packaging for such a small change.