End-to-end traceability is the ability to trace the flow of information, data, and processes from the beginning of a project or task to the end. It involves tracking the source of input, the transformations that occur to the data, and the final output. By creating a traceable record of each step in the process, it allows the data to be tracked and monitored to ensure accuracy, reliability, and compliance with regulations. End-to-end traceability also helps to prevent errors and identify points of failure.