The full form of GCLID is Google Click Identifier. It is a small string of numbers and letters. They create a unique badge for each web visitor. GCLID can track a user after he or she clicks on a PPC ad. Thus, you can understand whether that individual has been converted or not. If the individual has been converted, you can know the page where he or she has visited and the used method. You can involve Google Analytics to generate a perfect Analytical Report.