What is a common usage for the PCI standard in computer systems?

The PCI (Peripheral Component Interconnect) standard is primarily utilized for adding expansion cards to computer systems. This includes a wide variety of hardware components such as sound cards, graphics cards, network interface cards, and more. The primary function of PCI is to facilitate communication between the motherboard and any additional peripherals that are needed to enhance the system's capabilities.

When expansion cards are connected via the PCI standard, they can take advantage of the motherboard’s resources while providing specific functionality that may not be available through the motherboard’s integrated components. This allows users to upgrade or customize their systems according to their needs, such as adding a dedicated graphics card for better gaming or a new sound card for enhanced audio quality.

In contrast, other choices do not reflect typical uses of the PCI standard. Connecting optical drives generally involves interfaces such as SATA (Serial ATA) or IDE (Integrated Drive Electronics), while network connectivity is typically managed through Ethernet standards or wireless protocols. Enhancing video graphics performance can indeed involve PCI expansions, but the term itself is too vague and doesn't specifically point to the PCI standard's role in adding various expansion cards to a system.