Some people reading this will just keep reading it for the sake of it because they already know what the differences are. Believe it or not, however, there are plenty of people who do not understand the differences between a web site and a web page, and that's completely okay! In layman's terms, a web site can be described as a book while a web page can be described as a page from the said book.
This is a site...
...and this is a page from the site above
All in all, a site is a collection of pages. A site can also only have a single page but would still be considered a site. This is called the "index.html" page. It is the most commonly used default page for a site, even Neocities uses it! If you type in "/index.html" after your site, e.g., https://imnotgloomy.neocities.org/index.html, then it would go to the same page as your default site page.
Anyway, that's about it. It wasn't quite complated enough for me to have put it in "layman's terms," but that's whatever. I hope you learned something! I'm proud of you.