This is an example page. It differs from posts because it always stays in the same place and (on most themes) is displayed in the navigation bar. Most people start with an „About Us“ page with an introduction to potential site visitors. For example, there could be:
Hi! By day I work as a bike messenger, by night I’m an aspiring actor and this is my blog. I live in Berlin, have a big dog named Jack, like the Fantastischen Vier and a cold beer.
As a new WordPress user, you should go to the dashboard to delete this page and instead create a new page with your own content. Have fun!