What do controller cards do in a computer?

Controller cards are hardware components that enhance the capabilities of a computer by connecting to the motherboard’s electrical connectors. These cards can add features such as improved data storage, networking capabilities, or graphics processing, depending on their specific function.

In the context of this question, selecting the option about controller cards plugging into electrical connectors on the motherboard correctly identifies the basic operational aspect of these cards. They are designed to interface directly with the motherboard to communicate with other computer components, enabling them to perform their designated functions effectively.

While controller cards may also play roles in aspects like data management or network expansion, that relationship is secondary to the fundamental requirement of connecting physically and electrically to the motherboard for operation.