Wal-Mart's well-oiled assembly line of conveyer belts and machines that pick, pack and sort items at its massive warehouses is mesmerizing to watch.
The company has more than 130 distribution centers in the U.S. in addition to its 4,100 stores, both of which ship millions of items every year.
Here's one of the distribution centers in action:
Wal-Mart employs a number of unmanned machines — like the one below — to pick, pack and sort items. The company would not say how many of these machines it uses or who makes them.
This machine is taping up packages to be readied for shipping:
Another machine stamps packages with their shipping labels:
Despite all of the automated operations in Wal-Mart's warehouses, humans are still an integral part of the process.
Here's a worker selecting larger items from storage shelves using a forklift:
Wal-Mart offers five million products online, including the iPad, one of its top-selling items.
Walmart has sped up its delivery time by 15% over the last two years using an algorithm to locate and sort items that was developed by its Silicon Valley tech shop @WalmartLabs.
The company doesn't only rely on its warehouses to ship online orders. It also uses workers in its 4,100 U.S. stores who select items from shelves and package them for shipping.
Go to Wal-Mart's website to watch a video of the warehouse operations.