A CPLD, or Complex Programmable Logic Device, is an integrated circuit that can be programmed to perform specific logic functions. It consists of a matrix of programmable logic blocks and interconnections, allowing designers to create custom digital circuits. CPLDs are often used in applications like signal processing, data routing, and control systems. CPLDs are known for their flexibility and ease of use, making them suitable for both prototyping and production. They can be reprogrammed multiple times, which allows for design changes without needing new hardware. This adaptability makes CPLDs a popular choice in the field of digital electronics.