A PCI Mezzanine Card (PMC) is a type of printed circuit board (PCB) designed to be plugged into a mezzanine slot on a carrier board. This type of expansion card is commonly used to add functionality to existing computer systems or embedded systems.

The PMC form factor is based on the PCI bus, which is a high-speed interface used to communicate between components in a computer system. A PMC card typically has two connectors: one that plugs into the mezzanine slot on the carrier board, and another that connects to the PCI bus on the carrier board.

PMC cards can be used to add a wide range of functionality to a system. For example, they can be used to add additional network interfaces, storage interfaces, or processing power. They can also be used for functions such as encryption/decryption, graphics processing, or digital signal processing.

One advantage of PMC cards is that they can be easily swapped out or upgraded without having to replace the entire system. This allows users to add new features or upgrade existing ones as needed, without incurring the cost of replacing the entire system.

PMC cards are available from a wide range of vendors, and they typically come with software drivers and development tools to help users integrate the card into their system. PMC cards are also available in a variety of operating temperature ranges, making them suitable for use in harsh environments.

In summary, a PCI Mezzanine Card (PMC) is a versatile expansion card that can be used to add functionality to existing computer or embedded systems. With a wide range of options available, PMC cards can be used to add new features, upgrade existing ones, and customize systems to meet specific requirements.