Amazon has opened its first “Just Walk Out” grocery store in Europe in the UK.
The till-less shop in west London, named Amazon Fresh, allows customers to scan a smartphone app when they are entering.
Visitors shop as normal and are automatically billed when they leave thanks to the US firm’s technology.
So, what exactly is Amazon Fresh, how does the new store work - and will there be more shops opening in Britain?
Here is everything you need to know.
What is Amazon Fresh?
The new Amazon Fresh store in the borough of Ealing is totally reliant on technology.
It stocks hundreds of own-brand goods from UK suppliers, as well as third-party brands from Morrisons and Booths - supermarkets that Amazon has pre-existing ties with.
There is also an "Our Selection" brand for "premium" products, including desserts.
When it comes to buying their groceries, visitors scan a smartphone app when they enter the store.
Then, they only have to place a product in a bag, or carry it out the shop, to be automatically billed when they leave.
They do not need to scan items, in contrast with other retailers which rely on products being scanned into a smartphone or shopping device.
The shop also doubles up as a place to collect and return Amazon products purchased online.
Customers can return goods simply by scanning a code, without even having to repackage or relabel the item.
Amazon, which is the world's largest online retailer, says its new store provides a more “frictionless” experience for visitors.
"When you're finished, you're free to walk out," explained Matt Birch, director of Amazon Fresh Stores and an ex-Sainsbury's executive.
However, some campaigners have raised privacy concerns about the idea.
How does Amazon Fresh work?
Shoppers are not under any obligation to check that all their items are accounted for when they leave Amazon Fresh.
That’s how confident the US retail giant is about its technology.
The system was pioneered at the company’s Amazon Go stores in the US, which are similar to Amazon Fresh and opened to shoppers in 2018.
But recent advances in the technology means the system can now cope when shoppers select different types of the same product.
For example, before it could not tell the difference between varying magazines and greetings cards.
The technology in Amazon Fresh works by using hundreds of cameras and depth-sensors.
It also utilises software using deep-learning AI techniques.
Yet it does not involve facial recognition, with shoppers instead required to identify themselves by scanning a barcode displayed within their account in the Amazon Shopping app.
Amazon has said it will only associate information collected in-store with a customer's individual account for up to 30 days.
Could more Amazon Fresh stores open in the UK?
Mr Birch said he plans for further Amazon Fresh stores to open on some of London’s high streets, as well as in the city centre.
The Ealing store’s shop floor covers around 2,500 sq foot, so it is a lot smaller than a typical supermarket.
Additionally, Amazon runs seven Whole Foods Market supermarkets in the UK.
There have been recent rumours that the US company might try to expand in the sector by buying one of the bigger chains.
But the firm is offering to sell its Just Walk Out technology as a service that could be installed in other companies’ grocery stores.