Why is the expiration date of the root certificate longer than website certificate?

The expiration date of a root certificate is typically longer than that of a website certificate because root certificates serve as the trusted anchor for a public key infrastructure (PKI). They are designed to maintain a stable and trusted chain of trust over a longer period, minimizing the risk of disruption in trust relationships. In contrast, website certificates are issued for shorter durations to enhance security and allow for more frequent updates in response to evolving security practices and vulnerabilities. This difference ensures both stability in trust and adaptability to changing security needs.