An entity is a uniquely identifiable thing or concept, such as a person, company, place, product or event. Its properties and its relationships to other entities describe its identity.
What is an entity?
"Prague" is more than a string of characters. It's a specific city with a location, a country, a history and relationships to other places. That's how Google can connect the queries "Prague" and "capital of the Czech Republic".
The Knowledge Graph is one of the technologies Google uses to work with entities and facts. Not every mention on the web automatically becomes a verified fact in that graph.
Why meaning matters more than words
Semantic search assesses the meaning of a query and the relationships between concepts. An exact phrase match is only one of the ways to a relevant result.
Language models also work with representations of meaning, but you can't reduce them to one shared entity graph. Each model and search engine uses its own systems.
What it means for your site
Keep your name, offer, roles, prices and contacts consistent. Connect the person's profile, the company, the services and verifiable external sources so the relationships make sense to both people and machines.
Structured data can make the relationships more precise, but it has to match the visible content. Schema alone, or repeating the name, won't secure authority or a citation in an AI answer.