LanderLab has a small CMS (a content management system: the place where you write and keep the pages of a site). This is its Article Page, the window where a user writes a blog post.
On the left is the post itself, with a toolbar for bold, links, images, lists and embeds. On the right are the details every post needs: the slug for its address, a short excerpt, categories, the date, a cover image and the author.
Here it writes a post by itself. The title comes first, then the text with its bold, underlined and link parts, then a banner image drops in. At the end it fills in the details and presses Publish.