In the nodes you can add different media, such as text, film, sound and images. You can also make hyperlinks and embed films from external sites such as Youtube and Vimeo. There are also other resources you can embed, for example Slideshare. You can try to see if a resource is possible to embed by pasting a link directly in the node. If it is not possible to embed the resource, it will place itself as a link. If you want to see how each type of node is used and what content is suitable for it, there are examples in the loop Build a learning loop.