This will display the title of the page when a static page is set to show posts.
I show posts on my homepage…
It’ll do nothing.
If I, say, show posts on page titled News…
It’ll show News in H1.
This is used so that the title of the page is shown, whenever posts are shown on a page, but nothing when blog posts are shown on the front page (home page).
We do it because if it’s on home page… it will show the title of the first post, making it appear twice (once at the top in H1 and again when posts are looped through).