Java: What is the difference between @Transactional and programmatic transactions?

1// Declarative
2@Service
3public class OrderService {
4    @Transactional
5    public void createOrder(Order order) {
6        orderRepo.save(order);
7        inventoryService.reserve(order);
8    }
9}
10
11// Programmatic
12@Service
13public class OrderService {
14    @Autowired
15    private TransactionTemplate txTemplate;
16    
17    public void createOrder(Order order) {
18        txTemplate.execute(status -> {
19            orderRepo.save(order);
20            inventoryService.reserve(order);
21            return order;
22        });
23    }
24}