Computer storage is the hardware or software that allows users to save data. This information is stored for use in the future and can be retrieved even after a computer is shut down. This information is typically stored on magnetic or optical media, such as hard disk drives and data CD’s.

Storage technologies have come a long way, from the 5.25-inch disks that held 360 kilobytes in the 1980s to modern hard drives with capacities of several terabytes. These advances in technology have allowed computers to process larger amounts of input data and produce output faster than ever before. In addition, consumers have increased their demand for storage space, requiring new devices with greater capacity and speed.

A computer’s storage consists of two basic levels: primary and secondary. Primary memory is volatile, meaning that it loses information if the system shuts down. Secondary storage, which includes flash memory and hard disk drives, is nonvolatile, allowing the computer to retain its data when it is turned off.

The speed at which a device reads and writes information is what defines its storage performance. Modern flash storage devices are capable of a trillion read/write operations per second, and the latest SSD’s can achieve more than 3,000 IOPS. This high level of performance means that files can be loaded from storage more quickly, and output is able to be produced almost instantly.

Another important attribute of computer storage is random access, which enables the information on a disk to be pulled in any order. This is a significant improvement over the sequential access method that was the norm for older hard disk drives. The newest hard disk drives are configured with a random access feature, and most applications can take advantage of it.

Computers can also create backup copies of data that is on their primary and secondary storage. A common technique is to store the data on a device that is identical to the original one (referred to as mirroring). When something goes wrong with a single device, its copy can be activated and used to replace it without losing any information.

An alternative to mirroring is tiered storage, which automatically places data on different storage devices based on capacity, performance and compliance requirements. This can improve overall storage efficiency, reducing the amount of time and money that is spent on underutilized or overly expensive hardware.

A hard disk drive with a large capacity can be used as a back-up, but the best option for long-term storage is an SSD or solid-state drive. With no moving parts, an SSD requires less power than a hard disk drive to function and consumes less physical space. They are also faster and lighter than hard disks, and they can be more durable against accidental drops.

A hard disk drive has a mechanical spinning platter that manages the data, with an actuator arm reading and writing information to the disk. The actuator arm is guided by a control device, and the speed at which it reads or writes is what determines the storage performance. The latest hard disks can hold up to 2TB, so there is plenty of room for your files and programs.