Hardware devices that are not part of the main computer system unit and are often added later to extend functionality are called what?

Introduction / Context:
This question asks about the general term used for hardware devices that connect to a computer but are not built into the main system unit. Examples include printers, scanners, external drives and webcams. These devices expand what a computer can do, and knowing the umbrella term used for them is essential in computer awareness and office skills exams.

Given Data / Assumptions:

• The devices are hardware, not software.
• They are not part of the main system unit.
• They are often added later to provide extra features.
• Options include clip art, highlight, execute, peripherals and documents.

Concept / Approach:
Peripherals is the standard term for external devices attached to a computer. These can include both input peripherals such as a keyboard and mouse, and output peripherals such as a monitor and printer. Clip art, highlight and execute are terms related to software and editing, not hardware. Documents are files containing text or data and again are not physical devices. Therefore, peripherals is the correct term for hardware devices added to extend functionality.

Step-by-Step Solution:
Step 1: Identify that the question is about hardware devices, not software features. Step 2: Note that these devices are not inside the system unit but connect to it through cables or wireless links. Step 3: Common examples include printers, scanners, speakers, webcams and external storage drives. Step 4: The general term for such devices is peripherals or peripheral devices. Step 5: Option d, peripherals, exactly matches this definition. Step 6: Clip art refers to images inserted into documents and is purely software content. Step 7: Highlight is a text editing action used in word processors or other programs. Step 8: Execute is a command that means to run a program and is not a hardware device. Step 9: Documents are files such as text files or spreadsheets, not physical hardware.

Verification / Alternative check:
In computer textbooks and user manuals, you often see phrases like connect the peripheral to the computer or install the printer peripheral. Diagrams show the system unit in the centre with peripherals such as monitors and printers connected around it. This clear visual distinction confirms that peripherals is the noun used to describe hardware devices that are connected to a computer but not part of its core case.

Why Other Options Are Wrong:
Clip art, highlight and execute are all actions or content inside software applications and have nothing to do with physical hardware added to a system. Documents are data files that users create and save. Since the question specifically refers to hardware devices, all of these options can be rejected.

Common Pitfalls:
Students sometimes mix up terms when moving quickly between hardware and software sections of a syllabus. To avoid confusion, remember that peripherals are always tangible devices you can physically connect or disconnect from a computer. Words like clip art, highlight and execute should remind you of menus and commands inside software, not external hardware.

Final Answer:
Hardware devices added to a computer to extend its capabilities are called peripherals or peripheral devices.