StatelessComponent type mentioned in this answer has been deprecated because after introducing the Hooks API they are not always stateless.
A function component is of type React.FunctionComponent and it has an alias React.FC to keep things nice and short.
It has one required property, a function, which will return a ReactElement or null. It has a few optional properties, such as propTypes, contextTypes, defaultProps and displayName.
Here’s an example:
const MyFunctionComponent: React.FC = (): ReactElement => {
return <div>Hello, I am a function component</div>
}
And here are the types from @types/react 16.8.24:
type FC<P = {}> = FunctionComponent<P>;
interface FunctionComponent<P = {}> {
(props: PropsWithChildren<P>, context?: any): ReactElement | null;
propTypes?: WeakValidationMap<P>;
contextTypes?: ValidationMap<any>;
defaultProps?: Partial<P>;
displayName?: string;
}