Apple blames iTunes outage on DNS error. What does that mean?

Apple's App Store, iTunes, iBooks, and Mac App Stores were all down on Wednesday, while other Apple services such as Apple TV, iCloud, and FaceTime were working properly.

The Next Web (TNW) first discovered the problem in the US and UK App Stores and turned to readers to help figure out how widespread the problem was. The blog found that everyone from Armenia to Hong Kong was blocked from buying content through the various online stores.

As of press time, the problem has not been resolved, sparking Twitter hashtags such as #itunesdown and #appstoredown.

Apple issued a statement and an apology to CNBC, explaining that an internal mistake caused the outage.

“We apologize to our customers experiencing problems with iTunes and other services this morning," Apple says in the statement. "The cause was an internal DNS error at Apple. We're working to make all of the services available to customers as soon as possible, and we thank everyone for their patience.”

So what is an internal DNS error anyway?

Well, first off, "internal" means that the error occurred within Apple's own corporate network. As for DNS, it stands for Domain Name System. While computers access the Internet through IP addresses – codes made up of numbers separated by dots, such as 50.57.23.79 – DNS is a short cut for average humans. It works by allowing users to type simple names – such as csmonitor.com – into an address bar, rather than typing out the whole IP address for each website and server.

The whole process works by the DNS translating a domain name (csmonitor.com) into an IP address, so your computer will connect to the correct site.

DNS errors can occur when there's a breakdown in this system, either because a server is down or because there’s an issue with the DNS routing to correct domain.

If you want to know the moment that iTunes is up and running again, check out Apple's system status website.