Tape

A tape is a magnetically thin coated piece of plastic wrapped around wheels capable of storing data. Tape is less expensive than other storage mediums, but it is a much slower solution because it is sequential access and is often used for backing up large amounts of data.

Today, tape has mostly been abandoned for faster and more reliable solutions like disc drives, hard drives, and flash drives that are all direct access and cloud storage. The image is an example of magnetic tape taken by KENPEI and shared under the creative commons.

How much can a tape drive store?

The storage capacity of a tape drive all depends on the type of tape drive and technology being used. For example, the first tape drive introduced by Remington Rand in 1951 was only capable of storing 224 KB of data. Later tape drives released in the early 2000s were capable of storing several TB of data. For example, the IBM TS1155 generation 6 tape drive released in 2017 is capable of storing 15 TB of uncompressed data.

Magnetic media

Any storage medium that utilizes magnetic patterns to represent information is considered magnetic media. Good examples of a magnetic media and magnetic storage is a tape drive, floppy diskette, and hard drive.

Above is an example of the read/write head inside a hard drive. The electromagnetic write head polarizes tiny sections of the hard drive so they face up or down ("North" or "South") to represent the binary digits 1 or 0. Information is read by the read head, which detects the polarization of each section of the drive to understand the data that was written.

Sequential access

Alternatively referred to as serial access, sequential access is a method of retrieving data from a storage device. With sequential access, the device must move through all information up to the location where it is attempting to read or write. This method is often contrasted with random access, in which the device may move directly to a specified location in memory.

A common example of sequential access is with a tape drive, where the device must move the tape's ribbon forward or backward to reach the desired information. The opposite would be RAM (Random Access Memory) that can go anywhere on the chip to access the information.