Continuous delivery is a way of working that keeps each checked change ready to release. Think of a parcel that has been packed and inspected; it is ready to send when someone gives the go-ahead.
For a website, automated checks may run after each code update and prepare a version that could be deployed. A person may still choose when that version goes live.
Continuous delivery is not always the same as automatic release. In continuous deployment, passing changes can go live without a separate approval step; with continuous delivery, the release can remain a deliberate choice.