Only a few years ago, many people may have been unaware of what a data centre was.
These vast, warehouse-like buildings now support much of daily internet activity, from web searches and email to movie downloads and online banking.
They sit at the centre of the AI boom, housing the advanced chips and servers needed to power services such as ChatGPT and Claude.
But as their pace of growth accelerates, their electricity demands rise sharply, and environmental concerns mount, public backlash is growing in many parts of the world.
In the United States, data centres have become a prominent issue ahead of the 3 November midterm elections, with Republicans and opposition Democrats both opposing their expansion.
The divide has put opponents of data centre expansion on a potential collision course with US President Donald Trump, who has dismissed the concerns as a “sick conspiracy,” even as public anger intensifies.
Here is what to know about the data centre boom and why opposition is increasing.