What is the purpose of network interface cards?

The purpose of network interface cards (NICs) is primarily to enable computer connections over a network. NICs function as the hardware that provides the physical interface between a computer and a network, allowing the computer to communicate with other devices. They facilitate both wired and wireless connections, converting data from the computer into a format suitable for transmission over the network and vice versa. By doing so, NICs play a critical role in establishing the communication paths necessary for data exchange within local area networks (LANs) or connecting to the internet.

The other options address different aspects of network functionality. For example, cleaning and regenerating signals pertains more to repeaters or switches, which enhance signal strength and quality across longer distances. The notion of serving as a security measure could relate to firewalls or intrusion detection systems rather than the primary function of a NIC. Lastly, transmitting data over long distances is typically associated with different networking devices or technologies, such as routers and fiber optic cables, rather than the direct function of network interface cards.