Etymologically speaking, the word cylinder originates from the Greek "kylindros" which means "roller", and it is a solid geometric body that has two very similar flat and round or oval ends with a curved side., whose development is a rectangle. The characteristics of a cylinder are, the axis that is the fixed or immobile side around which the rectangle will rotate, then we have the bases that are the circles that generate the sides perpendicular to the axis; the height is understood to be the distance between the two bases; and finally there is the generatrix which is the opposite side to the axis, and this side produces the cylinder and it is worth noting that the generatrix of the cylinder is equal to the height. There are several types of cylinders, such as the rectangular one, it is when the axis is perpendicular to the base; the oblique when it is not perpendicular to the base and that of revolution, when it is limited by a surface that rotates in 360 degrees.
It is also customary to give this term to any piece or object that has this shape or appearance. Similarly , the device or mechanism that moves the latches of a lock when the key is inserted is called a cylinder. In the mechanics environment, a cylinder is a metal tube found in a car engine, where fuel mixes, and drives the piston and starts the engine and allows the car to move.
In biology cylinder is the extension or extension of a neuron, which almost always spreads and makes contact with other cells. And finally, in computing, this word is used to refer to a series of tracks organized horizontally on the hard disk.