A storage device can be defined as any piece of hardware whose main function is to store data and information The hardware that writes data to or reads data from a storage medium is called a storage device. Types of Computer Storage Devices
Computer storage devices can be classified into
Primary Computer Storage Devices
Primary storage refers to the computer's memory(RAM)
RAM (Random Access Memory)
It connects directly to the computer's CPU.
It is a volatile form of storage.
Volatile storage means that you totally lose data when you switch the system off. Secondary Computer Storage Devices
These storage devices are external in nature and non-volatile as compared to primary storage devices. These storage devices do not lose data even when they are turned off. These storage devices are not attached to the computer's CPU, it takes a longer time for the CPU to access them. These devices need to be formatted before they can store data Examples of secondary storage devices include CD and DVD, flash memory, floppy disks etc Tertiary Computer Storage Devices
Its main use is for storing data at a very large-scale. These devices require a database to organize the data that are stored in them, and the Example :tape libraries.
SECONDARY STORAGE DEVICES
It is also called auxiliary storage or external storage or backing storage. The devices of computer that store information such as software and data permanently are called secondary storage device . It is all data storage that is not currently in a computer's primary storage or memory. Types of secondary storage devices are magnetic disk, Hard disk ,floppy disk , CD Rom , magnetic tape etc...
Characteristics of Secondary storage devices
It will retain the stored information even if it is not constantly supplied with electric power.