camelCase vs. PascalCase: What's the Difference?
camelCase lowercases the first word and capitalizes subsequent ones (userName). PascalCase capitalizes every word, including the first (UserName).
As a convention, camelCase is for variables, functions, and properties. PascalCase is reserved for types — classes, interfaces, enums, and React components.
That single leading capital is enough to tell another developer: "this is a constructor, a component, or a type — not a value."