A closure is a device used to close or seal a container such as a bottle, jug, jar, tube, or can. A closure may be a cap, cover, lid, plug, liner, or the like. The part of the container to which the closure is applied is called the finish.Other types of containers such as boxes and drums may also have closures but are not discussed in this article. Many containers and packages require a means of closing, which can be a separate device or seal or sometimes an integral latch or lock.