Even if you're not familiar with the term "knowledge graph," you've probably had experience with Google's Knowledge Graph technology. Whenever detailed information about your search pops up directly on the search engine results page, that's the Knowledge Graph at work. For example, a Google search for "Benjamin Franklin" returns birth and death dates, works written, images and much more in a box placed prominently on Google's results page.
Yesterday, a digital marketer noticed that song lyrics are showing up in the SERPs. This is great for users but potentially ruinous for lyrics sites.