The internet is running out of IP addresses in few hours from now. The Internet Assigned Numbers Authority will be distributing the last five blocks of IP each with 16.8 million addresses to regional registries around the world on Thursday, according to Associated Press reports.

IP Address, or Internet Protocol Address, in simple terms is the unique name of a computer online. It enables identification and location of a particular computer and its user. The websites and the URLs we use to log in to a website also have IP addresses but generally have names like or to make it easier for the human brains to remember.

Now the version of the IP addresses the world is working on - IP version 4 - is running out. However, this does not mean that websites will not be reachable. It will just be 'business as usual' if everyone gets their job done, John Curran, CEO of the American Registry for Internet Numbers, or ARIN, one of five regional groups that dole out such addresses. ARIN covers the U.S., Canada and the Caribbean, told AP news agency.

The system now in use, called Internet Protocol version 4, has been around since the 1980s. While experts have known for years that the numbers would one day be depleted, their end is pressuring websites and service providers to move more quickly on technology to create more numbers, AP says. The addresses allow Internet users to reach the websites they're seeking and their e-emails to reach their destinations.

As the 4.3 billion version 4 numbers run out, service providers will give out IPv6 numbers, although only about 2 percent of websites now support it. Those few sites are among the most-visited sites like Google and Facebook, the news agency reported.

As Internet service providers run out of IPv4 addresses, they'll have to give subscribers IPv6 addresses. The challenge lies in connecting them to websites that have only IPv4 addresses. In essence, IPv4 and IPv6 are different languages. Several translation technologies are available, but they haven't been tested on a large scale, Curran said. That could lead to problems reaching some websites, or slow surfing.

We're estimating how these boxes will work, but we haven't seen one deployed with tens of thousands of customers on it yet, Curran added.