What is the primary function of expansion slots in a computer?

Expansion slots are designed to enhance a computer's capabilities by allowing the installation of additional components such as graphics cards, sound cards, or network cards. This modular approach facilitates upgrades and customizations, enabling users to improve performance or add functionality according to their needs. For instance, a dedicated graphics card can significantly enhance visual performance for gaming or graphic design, while a sound card might improve audio quality.

The other options do not accurately describe the primary role of expansion slots. Connecting to the internet typically relies on network interfaces, which can be integrated into the motherboard or connected via an expansion slot. Providing power to the motherboard involves a separate power supply rather than the function of expansion slots. Additionally, while components within expansion slots might contribute to data storage or processing, expansion slots themselves do not store data directly. Their main purpose is to facilitate the addition of new hardware components.