Cylinder

The word cylinder has several meanings:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Cylinder (geometry), a three-dimensional geometric surface
• Cylinder (engine), the space within which a piston travels in an engine
• Cylinder (disk drive), a unit of data division on a hard disk drive
• Gas cylinder, containers used to store compressed gases or compressed air
• Phonograph cylinder, the dominant medium of audio storage from the 1870s to the 1910s and in limited use (such as in the dictaphone) through the mid 20th century
• In firearms, the cylinder is the rotating device that contains the firing chambers of a revolver.
• A type of lens and a form of refraction error.