What is an adaptor card?

An adaptor card is a hardware component inserted into a computer's motherboard that provides additional functionalities. These cards enhance the capabilities of the computer, which could range from improved graphics performance, sound processing, or network connectivity, depending on the type of adaptor card. For example, a graphics card allows for better video rendering and is essential for gaming, while a network card enables wireless or wired internet access.

The other options describe components or tools that do not fall under the definition of an adaptor card. A type of power supply component refers specifically to parts that provide electrical power to the computer, while a software tool for system optimization pertains to applications designed to improve system performance without adding hardware. Lastly, a visual component of the motherboard is not applicable, as an adaptor card itself is an independent hardware piece that connects through slots on the motherboard to expand the system's capabilities.