The PANTECH PC Card (UDP) Windows driver is a device driver for a Pantech PC Card that enables your Windows computer to interface with the device. Typically, this refers to a Pantech 3G or 4G USB modem or mobile broadband device that connects to a cellular network. "UDP" stands for User Datagram Protocol, which is a protocol used for sending data over networks. However, in this context, the term "UDP" is more likely referring to the PC card used for mobile internet connectivity, possibly a mobile hotspot or a data card.
Pantech is a manufacturer that provides USB and PC card-based devices for mobile broadband, especially for cellular network connections such as 3G and 4G LTE. The driver for these devices allows your PC to recognize and communicate with the card when it is plugged into your laptop or desktop.