This is an example page. It differs from a blog post in that it always stays in the same place and (in many themes) appears in the navigation menu. Many people start with an About page that introduces them to site visitors. A presentation like this might appear:

HI! I'm a cycling delivery driver by day, aspiring actor by night and this is my website. I live in Los Angeles, I have a big dog named Jack and I like piña coladas. (And catch the rain)

…or something similar:

The XYZ Gadgets Company was founded in 1971 and has been providing the public with excellent quality gadgets ever since. Located in Fantasyland, XYZ employs over 2,000 people and makes all sorts of cool gadgets for the Fantasyland community.

As a new WordPress user, you should go to your Noticeboard to delete this page, and create new ones for your content. Have fun!