A storage medium is the physical material on which a computer keeps data, instructions, and information. There is a variety of storage media available as shown in the figure below.
A reasonably priced USB flash drive can store 1GB of data (approximately one billion bytes) and a typical hard disk has 320 GB (approximately 320 billion bytes) of storage capacity. Items on a storage medium remain intact even when power is removed from the computer.
A storage device records (reads) and/or retrieves (writes) items to and from a storage medium.
Each time a storage device transfers data, instructions, and information from a storage medium into memory, a process called reading, it functions as an input source. When a storage device transfers these items from memory to a storage medium, a process called writing, it functions as an output source.
For example you can use a card reader/writer to transfer stored items, such as digital photos, from the memory card to a computer or printer.
Storage devices like CD readers/ Floppy disk drives, etc often function as a source of input because they transfer items from storage to memory. Many computers have storage devices like card readers already embedded on the motherboard and accessible through a port on the system unit.
Please refer to the following sources for backup information. When searching for information on the internet, dont just google... Always consider reliable sources by evaluating the kind of website and giving priority to more credible websites, such as academic institutional websites. Read more tips here.
- International General Certificate of Secondary Education (IGCSE) ICT website for University of Cambridge International Examinations
- General Certificate of Secondary Education (GCSE), Computing Webbsite, England
- Institute of Science and Technology (SRM University, India)
- Internationally Published TextBook: Computing Essentials Book by Timothy J O’Leary
- Department of Computer Engineering, Boğaziçi University, Turkey
- Book Extract: Computer Hardware Input-Output-and-Storage (23 downloads)