HTML looks like this:
<html>
...
</html>
“…” is whatever that goes between those tags, omitted for brevity
You should view an HTML “file” as a “document”. You will see why when we delve into JavaScript.
index.html
HTML
What kind of files are also called documents? DOCX, aka Word documents.
And how do you read DOCX? With the application Microsoft Word.
So HTML, also a kind of document, is read by a browser instead of MS Word.