What is the primary function of a Network Interface Card (NIC)?

A Network Interface Card (NIC) serves the crucial function of connecting a computer to a network, enabling communication between devices. It acts as the hardware that facilitates the exchange of data over a network, whether wired or wireless. Each NIC has a unique identifier known as a MAC address, which helps in the identification of the device on the network and ensures that data is sent to the correct location.

The connectivity provided by a NIC is fundamental for networks to operate effectively, as it allows for data to be transmitted and received from other devices, routers, and the internet. Without a NIC, a computer would not be able to communicate with other devices or access network resources, making it an essential component in both local area networks (LANs) and wide area networks (WANs).

In contrast, the other options do not capture the primary capability of a NIC. While some NICs may provide wireless communication, which could relate to the first option, the core purpose remains centered on networking. Testing network security is not a function of a NIC, nor is data storage management—both duties belong to different types of hardware or software. Thus, connecting a computer to a network is the most accurate description of a NIC's primary role.