Because the web is a stateless system, each connection that a browser makes to a web server is unique to the web server. However, many applications must keep track of users as they move through the pages within the application. This is the definition of client state management.
ColdFusion provides tools to maintain the client state by seamlessly tracking variables associated with a browser as the user moves from page to page within the application. You can use these variables in place of other methods for tracking client state, such as URL parameters, hidden form fields, and HTTP cookies.