Storage devices are also called secondary storage devices / backing storage devices / external storage devices or auxiliary storage devices. Storage devices are the computer hardware used to remember/store data. Currently, they are mainly used with the mainframe computers. Depending upon the storage capacity, access rate and volatility, data storage can be divided into primary storage and secondary storage. After learning the hierarchy of storage, it is reasonable to say that there are 4 types of computer storage devices: primary, secondary, tertiary and offline storage devices. Early computers used delay lines, magnetic drums, William tubes etc. Other terms for storage device is storage medium or storage media. As for the common secondary storage devices , they can be further divided into internal and external storage devices of computer according to their location, inside or outside of computers or servers. In the storage devices, information or data can be stored temporarily or permanently. What is Storage Devices : In computing, storage device is a hardware which can store data and files. The sequential types of storage devices for computer systems consist of magnetic tapes which are economically friendly besides being compact, reliable and faster data retrieval and storage. Storage devices are used to store data and instructions permanently. A storage device is one of the basic elements of any computer device. Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data.It is a core function and fundamental component of computers. It comes in different shapes and sizes depending on the needs and functionalities. They are mostly preferred for full backup. In most cases, any type of file can be added to a storage device. It almost saves all data and applications in a computer except for hardware firmware. These devices provided an extremely low access rate. A storage device is a physical piece of hardware that is used to store data. But with the invention of transistors, radical changes were introduced in the memory implementation techniques. Types of Storage Devices. Generally there are two type of Storage Devices exist -Primary Storage devices and Secondary storage device. Some storage devices are universal and can be used with a variety of hardware. : 15–16 The central processing unit (CPU) of a computer is what manipulates data by performing computations. There are many types of storage devices, each with their own benefits and drawbacks. Below are explanations about different storage devices. for storing data. List of storage devices.