We've started covering Schema.org schemas - not all websites use them but some do. They include things like MedicalBusiness and SportsClub - these are defined bits of indexable data that allow robots like Google to know the content of the site.
See them all here -https://trends.builtwith.com/framework/schema
The picture above is of a woman using a Le Creuset to cook what looks like scrambled eggs whilst smiling and looking away. Her left hand is very close to the gas but it looks like the gas is switched off. The picture has no relevance to this blog post, robots probably won't get that hence why Schema data was created.