In computer storage technology, a compact disc (CD) is an example of which type of data storage medium?

Introduction / Context:
A compact disc, commonly known as a CD, is one of the earliest and most popular forms of removable digital storage used for music, software distribution and data backup. This question checks whether you understand the basic category of storage technology to which a CD belongs. Knowing the difference between optical, magnetic, mechanical and other types of media is a core part of computer fundamentals and appears frequently in general knowledge and computer awareness exams.

Given Data / Assumptions:

• We are talking specifically about a compact disc (CD) used to store digital data, audio or software.
• The question asks for the type of data storage medium that a CD represents.
• Options mention optical, mechanical, electrical, magnetic and electrochemical storage categories.
• We assume standard definitions of these storage types from computer hardware basics.

Concept / Approach:
A compact disc stores data using tiny pits and lands on its surface that are read by a laser beam. The laser light is reflected differently by pits and lands, and a sensor converts these differences into digital bits. Because a laser and light reflection are used for reading and sometimes writing data, a CD is called an optical storage medium. In contrast, magnetic storage uses magnetised surfaces, mechanical storage uses physical movement or punched cards, and semiconductor storage relies on electronic charges in chips. CDs clearly fit the optical category, not the magnetic or purely mechanical categories.

Step-by-Step Solution:

Verification / Alternative check:
Computer hardware textbooks group CDs, DVDs and Blu ray discs together as optical media because they all use laser light for reading and writing. They contrast this group with magnetic media such as hard disks and floppy disks, and with solid state storage like USB flash drives and SSDs. Specifications for CD drives also mention laser wavelength and optical reading mechanisms. These consistent descriptions confirm that a compact disc is an optical storage medium, not a magnetic or purely mechanical device, so the optical option is correct.

Why Other Options Are Wrong:

• Mechanical storage device: While a CD spins mechanically, the actual data reading is optical, not purely mechanical storage like old punched cards.
• Electrical semiconductor storage: Describes solid state memory chips such as RAM or flash drives, not discs read by lasers.
• Magnetic storage medium: Used for hard disks and tapes that rely on magnetised coatings, not for CDs.
• Electrochemical storage device: More related to batteries and energy storage, not to digital data discs.

Common Pitfalls:
Some learners confuse CDs with hard disks because both are round and spin during operation. This can lead them to choose magnetic storage by mistake. To avoid this, remember that CDs, DVDs and Blu ray discs are always read using lasers and are therefore optical media. Hard disks and tapes, which are sealed and never directly visible while operating, use magnetic technology. Keeping these groups separate in your mind will help you quickly answer similar exam questions about storage types.

Final Answer:
A compact disc (CD) is a data storage medium of the type Optical storage medium.