This is a sample page. It differs from posts because it always stays in the same place and (for most themes) appears in website navigation. Most start with an imprint, privacy statement or “About us” page to introduce themselves to potential visitors to the site. There could be for example:
Hello! During the day I work as a bike Messenger, at night, I’m an aspiring actor, and this is my site. I live in Berlin, have a big dog named Jack, like piña coladas, but less (without umbrella) to be left in the rain.
… or something like this here:
XYZ 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 city dwellers 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 site. Have fun!