We talk about "the cloud" as if it were a magical, even invisible, force. But exactly what is it? Even the simplest definition of the cloud - a place for data to be stored remotely instead of locally - doesn't always apply. For Hong Kong in particular, the cloud is anything but remote.
The news that Apple is to begin building a data centre in the city next year - the company's first in Asia, and primarily to fuel the iPhone and iPad's iCloud backup service - is a timely reminder that far from being out of sight, out of mind, the cloud is actually in our backyard.
Each time you update your status on Facebook, chat on Yahoo, or send an e-mail from Hotmail, you're using the cloud. Google, China Mobile and Verizon are just a few big names with data centres in Hong Kong's Tseung Kwan O industrial area, which is fast becoming Asia's main hub for such facilities.
"Hong Kong's data centre sector has grown rapidly in recent years," says Antony Ma, a consultant for North Asia at Verizon Enterprise Solutions. "The demand for data centres in the coming years is also on the rise. The government is committed to positioning Hong Kong as the prime location for data centres in the Asia-Pacific region."
The area's proximity to the mainland is the main attraction, although this is not just a Hong Kong phenomenon. "There has been a rapid demand spike in the data centre market across the Asia-Pacific region and globally in recent years," says Ma.
He's right: the total amount of data stored in the cloud surpassed 1.8 zettabytes last year. That's 1.8 trillion gigabytes, and a growth factor of nine in five years. It's not totally clear where all of that data actually exists.
"The world's largest technology companies tend to dominate the sector, but most are very secretive about the number and location of facilities they have, because they don't want to give away competitive advantages," says Edward Jones, CEO of PMB Holdings, which has recently expanded into the data centre market.