A Programmable Logic Device (PLD) is an electronic component used to build digital circuits. Unlike fixed-function devices, PLDs can be programmed to perform specific logic functions, allowing for flexibility in design. They are commonly used in applications such as data processing, control systems, and communication devices. PLDs come in various types, including Field-Programmable Gate Arrays (FPGAs) and Complex Programmable Logic Devices (CPLDs). These devices can be configured by the user after manufacturing, enabling rapid prototyping and customization. This adaptability makes PLDs popular in industries like telecommunications, automotive, and consumer electronics.