Every day, the world produces more than 2.5 trillion gigabytes of data, a figure that's growing exponentially.
We're creating so much more data than we used to that at any one time, it's estimated up to 90 percent of all the data ever produced is less than two years old.
This explosion in the amount of information we're producing is called 'big data'. In the past, the little data we produced was largely inaccessible, kept hidden away in cabinets, manila folders and individual hard drives.
Technology has changed all that, in particular the internet and computers with processing power we only dreamed of in the past.
Big data is useful for businesses, because it allows them to track trends and compare sets of information that previously wouldn't have been available.
To give an example, Lillian Grace of Figure NZ says florists can not only compare their sales against other florists, but track the ebb and flow of funerals and weddings in their area. Previously this information was buried in the back pages of the newspaper -- now much of it is available online.
If a florist decided to put an advert for their store on Facebook for Valentine's Day, they can use that social network's massive collection of data to target their marketing to those most likely to buy flowers.
Rather than spend a fortune on TV advertising and having it go to waste, instead they're able to choose exactly who sees the advert -- for example, men in a relationship who live within a certain distance of the store -- and only pay when that demographic sees it.
Big data is also proving useful for Government agencies. Deputy Prime Minister Bill English has seen how several agencies collect information on clients, but don't have the overall picture; by combining the data, he thinks they'll be able to make better-informed decisions.
In the US, health researchers are using big data to track outbreaks of disease. The recent Ebola outbreak, for example, was spotted by Boston Children's Hospital's HealthMap service nine days before the World Health Organization by monitoring data from social networking sites, government websites and local news reports.
There are concerns however that big data could be used to spy on people. The sheer amount of information we now put online makes it a lot easier to keep tabs on people, without necessarily having to resort to traditional espionage tactics.
Big data isn't really anything new -- it's just a lot, lot bigger than it used to be, and technology is now making it useful.