What component utilizes an RJ-45 port for network connectivity?

The Network Interface Card (NIC) is designed specifically for network connectivity and commonly uses an RJ-45 port to connect to Ethernet networks. The RJ-45 connector accommodates twisted-pair cables, which are the standard cabling used in most wired networks. The NIC allows devices, such as computers and printers, to communicate with each other over a local area network (LAN) and is essential for connecting to the internet.

Other components listed do not serve the same purpose. A graphics card is responsible for rendering images and does not require a network connection. A power supply unit provides electrical power to the computer but is not involved in network communication. A hard drive serves as storage for data but does not facilitate network connectivity. Hence, the NIC is the critical component for using an RJ-45 port in a networking context.