This is an example page. It differs from posts because it always remains in the same place and is displayed in the website navigation (in most themes). Most start with an imprint, privacy policy or an “About us” page to introduce themselves to potential website visitors. For example, it could say:
Hello! By day I work as a bike courier, by night I’m an aspiring actor and this is my website. I live in Berlin, have a big dog called Jack, like piƱa coladas, but not so much being left out in the rain (without an umbrella).
… or something like that:
The XYZ company was founded in 1971 and has been supplying the public with high-quality products ever since. At its location in a small city, the company employs over 2,000 people and supports the city’s residents in many ways.
As a new WordPress user, you should go to your dashboard to delete this page and create new pages and posts for your website. Have fun!