Every Blog is a Website, but not every Website is a Blog
A Website is literally a site on the web, here web meaning the Internet. It’s how you would term a place where construction is ongoing as a construction site.
Thus, every blog, e-commerce store, magazine page you visit online is essentially a website.
When you visit the Amazon website, you are accessing a single website, but with multiple webpages, each product you click on, opens its own page containing information for the said product.
A blog is also a website, usually containing multiple pages as well. However what differentiates a Blog from every other website is that it is a platform for opinions.
With blogs, you have one (or sometimes multiple) person(s) expressing their opinions towards a particular topic, whereas on a website such as Amazon, you are navigating pages with product information.
A courier service website for example, displays all the relevant information for the courier service, and how a potential customer can reach the service. While you see all this information, you aren’t reading through an opinion, thus making this a website and not a blog.
Also, just because a page has a comment section on it, doesn’t make it a blog, if there isn’t a subject channeling their opinions (with or without information), it isn’t a blog.
This clarification isn’t for you to turn into a keyboard warrior every time someone misidentifies a blog, but rather to understand the core meaning of a blog, and what differentiates it from every other website.