A process flow diagram (PFD) is a visual tool used to illustrate the sequence of steps, tasks, or activities in a process. It uses standardized symbols, such as ovals for start/end points, rectangles for actions, and diamonds for decision points, connected by arrows to show the flow. Commonly used in industries like manufacturing, engineering, and business, PFDs provide a clear, high-level overview of processes, making it easier to analyze, optimize, and communicate workflows. They are valuable for identifying inefficiencies, troubleshooting issues, and training stakeholders by offering a structured representation of process operations and their interconnections.