E-commerce simplifies the shopping experience for both consumers and vendors. For consumers, they don't need to leave home and almost everything can be bought online. Especially for things which are not sold in nearby shops. Despite saving time, they're also able to research products and compare prices among retailers. For vendors, since the consumers overcome geographical barriers, they're able to send the products to consumers directly no matter where they are. Although online shopping is convenient, it's also a big challenge for both consumers and vendors to track their parcels and make sure it can be delivered on time. So we have various kinds of tracking tools to help with that. It is obvious that general consumers only have few parcels need to be tracked after shopping online. While vendors usually need to track hundreds or even thousands of parcels to make sure that all their customers can receive their product in time. And they can also do something once ther...