As Whatsapp continues to build on its e-commerce potential, it's continually adding more ways to facilitate connection between buyer and seller, and make it easier for user to buy items via the messaging app.

So the latest addition of WhatsApp is 'Carts' which enable WhatsApp user to add items as they engage with a business, then submit a larger order all at once via the app, with carts, users can browse a catalog, select multiple products, and send the order as one WhatsApp message to the business.
WhatsApp Carts is the latest in a range of ecommerce tools being added to WhatsApp as it look to maximize its monetization potential.Advertisements in Whatsapp proved unwelcome , so parent company Facebook has now shifted its focus to constructing a digital market inside the messaging community.

As explained by whatsapp :
"Starting today, we are excited t bring carts to whatsapp.Whatsapp cart are enormous when messaging business that typically sell multiple items at once,like a local restaurant or clothing store.This will make it simpler for business to keep track of order inquiries, manage requests from customer and close sales"
The process is simple - as you can see in the above sequence, as users find the items they want to buy in the app, they will now be able to tap "add to cart" as they go.Once you have finished shopping, you can send your cart as a message to the seller to submit your full order.