Questions for Working With C++

In the .h file for an actor there are two publics::

class [GameName]_API AMyActor : public AActor
{
    GENERATED_BODY()

public:
    // Sets default values for this actor's properties
    AMyActor();

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

public:
    // Called every frame
    virtual void Tick(float DeltaTime) override;
};

Is there a reason for this? Should only certain things be put under each one?