I created a component in c++. What's the difference between adding class before the component and not adding class?

UCLASS()
class MYTOWERDEFENSE_API ATowers : public ARuleOfTheCharacter
{
GENERATED_BODY()

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "BaseAttribute", meta = (AllowPrivateAccess = "true"))
	class USphereComponent * AttackRange;
}