How do expansion cards benefit a computer system?

Expansion cards enhance a computer system primarily by providing additional functionalities not included on the motherboard. This is a crucial aspect of computer architecture, as motherboards come with a set of integrated components that may not cover all user needs or specific use cases.

For instance, a sound card can be added to improve audio quality for media consumption or professional sound editing, while a graphics card can be installed to boost graphical performance for gaming or graphic design tasks. Network interface cards can provide upgraded connectivity options, such as faster Ethernet capabilities or wireless support.

While improving power efficiency, adding extra processing cores, or increasing storage capacity may be relevant aspects of various computer upgrades, these are typically not the primary functions of expansion cards. Expansion cards specifically target the enhancement of performance or capabilities in specialized areas, fulfilling specific user requirements that the onboard components do not address.