The correct way is using heading becouse a HTML document is made to be read by a browser and be indexed by a search engine, in this sense, the search engine need to know that a title is a title, the way to help a search engine is using headings.
The headings are

until

there aren’t more.
If you do a little experiment using several heading you will see how the browser display the first one more bigger than the second, and the second will be more bigger than third.

This is the correct way to present a HTML document on internet.

About the tag, as we saw, this tag is set inside the tag and you could think that this is not useful but is the real document name and It will be display into the browser, above, close to the favicon.