Web page and Website

Web page noun - A document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser.

Website and web page are semantically related In some cases you can use "Website" instead a noun phrase "Web page".

Website noun - A computer connected to the internet that maintains a series of web pages on the World Wide Web.

Web page and website are semantically related in group of connected web pages topic. You can use "Web page" instead a noun "Website".