Physical devices of a computer:

Hardware is the correct answer because it refers to the physical components of a computer system. These components can be touched, seen, and manipulated. They are responsible for the processing, storage, and input/output functions of a computer.

Explanation:
Hardware is a broad term that encompasses all the physical components of a computer system. These components can be categorized into different types based on their functions and usage. Some of the commonly known hardware devices include:

1. Central Processing Unit (CPU):
The CPU is the brain of the computer. It interprets and executes instructions, performs calculations, and controls the operations of other hardware devices.

2. Random Access Memory (RAM):
RAM is the temporary storage space where the computer stores data and instructions that are currently being used. It provides fast access to data, allowing the CPU to perform tasks efficiently.

3. Hard Disk Drive (HDD) or Solid-State Drive (SSD):
These are storage devices used to store data permanently. They provide long-term storage for the operating system, software applications, and user files.

4. Motherboard:
The motherboard is the main circuit board of the computer. It provides a platform for connecting and integrating various hardware components, including the CPU, RAM, and storage devices.

5. Input Devices:
These devices are used to input data and instructions into the computer. Examples include keyboards, mice, scanners, and microphones.

6. Output Devices:
These devices display or present the processed information to the user. Common examples include monitors, printers, speakers, and projectors.

7. Peripheral Devices:
Peripheral devices are additional hardware components that can be connected to the computer system to enhance its functionality. Examples include external hard drives, USB flash drives, and webcams.

Conclusion:
In summary, hardware refers to the physical devices of a computer system. These devices are essential for the functioning of the computer and include components such as the CPU, RAM, storage devices, input and output devices, motherboard, and peripheral devices. Software, on the other hand, refers to the programs and instructions that control the hardware and enable the computer to perform specific tasks.