So what is Drupal 'Paragraphs'?
Paragraphs is completely new method of adding content to a page in various styles. For example, you may have a blog post which is very text heavy and requires a two column layout or you may have only minimal text but need a full page image mixed in with your article... this is where paragraphs comes in.
Rather than just adding your text to the 'body' field and the big image to the 'image' field and then letting the layout of the page be decided by the designers templates, now you can choose from a range of totally customisable 'paragraphs'.
The best way to really show how this works is to actually use paragraphs for this blog post.
So the text you have just read was added to this blog post via a 'paragraph' I set up called SINGLE COLUMN... and hey presto the text is laid out in a single coloum.