The hub and spoke framework is a simple way of organizing your content by grouping articles by topic and then internally linking between them. Think of them as interlinked collections of content about a similar topic.
Typically a hub page is a high-level guide about a topic and the spokes are subpages covering other parts of the main topic. Internal links then connect each topic hub to it's related spokes.
You might have also heard them referred to as content hubs, silos, pillar posts and clusters. Whatever you call it, the end goal is the same: to create a logical structure so that Google and users can find your content.