The hard drive in a computer system will hold the most information.
Compact Disc.
A computer is made up of many technical systems. The registry is a special database that holds key information about your system, including the device drivers.
A CD-ROM (using a player) is an input device because it holds information that is readable. There are writable and re-writable CD's which allow you to add or remove information making it an output device (storage device) as well.
The most popular such device is the computer - the very device with which you asked that question, and with which I am answering it.
flash
Blu-ray
cassette
The device that holds the ammunition.
SDHC cards.
Anything that uses the most recent technological information. A screw driver at one time was a technological device.
no cd is a storage device as it holds data an output device would be a monitor or speakers.
input