What variable type can be used to store session data during the checkout process?

Using a session variable during the checkout process is crucial because it allows for temporary storage of data that needs to be maintained throughout the user's journey without persisting beyond their session. Session variables are designed to hold information specific to an individual user session, such as cart contents, user selections, and other temporary data relevant to the checkout process.

This approach is ideal for maintaining user context and ensuring a seamless checkout experience, as session variables can retain data across different pages while the user is actively engaged in the checkout process. Once the session ends, which usually occurs after the user leaves the website or after a timeout, the data stored in session variables is automatically cleared, ensuring that no unwanted data remains.

In contrast, other types of variables either retain information longer than necessary (like persistent variables which save data even after the session ends) or are not intended for this purpose. Temp variables are typically used for short-lived data that doesn't need to persist across requests, and state variables can carry different meanings in various contexts, making them less appropriate for session-specific data handling during checkout. Therefore, session variables are the most fitting choice for managing checkout-related information securely and efficiently.