1.2 Information Storage Media

There are several different methods of storing large amounts of data, from traditional paper-based methods to modern magnetic hard drives.


Mutability is a keyword that means whether a storage device can have its data changed or whether it is read-only. A mutable device can be overwritten, but an immutable device is permanent and read-only once data has been added.


Magnetic Storage

Magnetic storage includes devices such as magnetic hard disk drives (HDDs) and magnetic tape.


Magnetic storage is generally cheaper per gigabyte than other storage mediums such as solid-state storage.


This type of storage has a high capacity, with new desktop HDDs averagely containing 1TB of possible data storage.


Magnetic storage is often used for backing up files because of the high capacity.


Reading from magnetic storage or writing to it is slower than solid-state storage because of the moving parts.


Optical Storage

Optical storage uses laser technology to read data from a disc, such as a CD, DVD or Blu-Ray.


Optical media is cheap to bulk purchase and, because it is so thin, it is very portable.

Optical storage is typically used for entertainment media, such as music CDs, movie DVDs and games.


A drawback of the thinness of a disc is the tendency it has to snap or become scratched to the point of data corruption.


Optical storage has a low capacity - less than 1GB on a CD and less than 5GB on a DVD.


Solid State Storage

Solid-state (also known as flash) storage includes devices such as USB sticks, memory cards and solid-state drives (SSDs).


Solid-state storage is the fastest secondary storage medium because it contains no moving parts, so it can read and write data very quickly.


Solid-state devices are usually external, so they are portable and can be carried on a person in a pocket or a bag.

A drawback is that solid-state storage is more expensive per gigabyte than magnetic storage; a 1 TB SSD can be twice as costly as a 1 TB HDD.

Paper Storage


Paper storage includes printed or hand-written documents, notes, forms, schedules and maps. Paper is relatively inexpensive in small quantities, but it can take up much space compared to small devices like USB sticks.


Producing paper is environmentally damaging and requires physical security methods to keep safe. 

Paper, such as a timetable, can be written on if times change and easily carried on a person. However, paper in the form of an essay must be re-printed to add changes.

Question Corner

Information Storage Media:

a. For magnetic, optical and solid-state storage rank these mediums in terms of capacity, durability, portability and speed.

b. For the following scenarios justify which secondary storage medium should be used and why it is the most appropriate:

1. Sending videos and pictures to family in Australia through the post.

2. Storing a presentation to take into work.

3. A journalist taking notes during a speech.

4. Backing up an old computer with thousands of files to a storage device.                

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