The EF232 PCI-DUAL SERIAL is a PCI-based serial port card that provides two serial ports (COM ports) for systems that need additional serial communication capability. These types of cards are commonly used for connecting devices like modems, printers, industrial equipment, or older peripherals that rely on serial communication (RS-232). The "EF232" typically refers to the chipset or model, and the "PCI-DUAL" means the card has two serial ports.