The Knowledge Pages (Atlas) web part is a pre-configured In Focus web part. This web part is similar to the Knowledge In Focus (Atlas) web part but shows only Knowledge Pages, excluding other types of Knowledge such as Documents.
Each tile shows the title, image and date for the article. Users can go to a specific article by clicking the title or image, and page through the available Knowledge using the arrows at the top right.
From Atlas 2.3 onwards you can click the ellipsis (...) in the bottom right to see additional options:
Add Knowledge Pages
Knowledge Pages can be created via the Add It wizard. To see how, click here: Adding Knowledge Pages
Edit or Delete existing Knowledge Pages
To Edit or Delete Atlas content please check this article: Edit or Delete Atlas content
For Knowledge articles, because these are Pages you can also Edit them by navigating to the specific page and clicking Edit in the top right.
You can customise the layout and query of a Knowledge In Focus web part by editing the page, then editing the web part and modifying the configuration options. All the configuration options for In Focus web parts are described in the linked article: Configuration for In Focus web parts