The IANA transition is an important event that is vital for the Internet, but if you hadn't been told about it you wouldn't notice it. The change is fundamental, but will change relatively little day to day. IANA is a collection of jobs, mostly administrative, that sit at the core of the Internet.
IANA stands for Internet Assigned Numbers Authority, and its job is to serve as the authoritative record of various important records vital to the central coordination of the Internet, including the management of the root zones of the domain name system. The root zone includes the records of what top level domains (eg .com or .au) exist, and how to find the information needed so those names can be used.
It also records protocol parameters needed by people who create internet software, coordinates handing out IP numbers and the ASN numbers used for routing, and a range of other jobs, such as running a couple of special domain names itself, and keeping a list of time zones. Its role is vital, but relatively simple, simply to sit at the core of the Internet and be a clear, unambiguous, authoritative place to keep these vital records. These important jobs have been performed by a department of ICANN since 1998, and after the transition they will continue to be performed in almost exactly the same way by exactly the same people.
So what has changed?
The vital thing that has changed is not the role or function of IANA itself, but who authorizes its work and performs oversight to ensure that it is doing its job correctly. Since 1998, ICANN has performed that work under the a (no fee) contract from the National Telecommunications and Infrastructure Commission (NTIA), part of United States government Department of Commerce, and the NTIA have had a very minor role in day to day operation (essentially signing off on root zone changes, something they have never not done). But this contract has required regular renewal, and that has meant that the US government has been able, through that necessary renewal process, to exercise a great deal of oversight over IANA, and more broadly ICANN, operation.
That has changed. There is no contract, the IANA role is now performed by ICANN without US government approval, the US government has no role in root zone changes, and the oversight of IANA is now performed by representatives of the Internet community. Exactly hos this Internet community oversight is performed has been discussed over the last couple of years by hundreds of representatives of the global Internet community, including all the major organisations that interact with IANA directly, and many representatives of ordinary Internet users and other interested people. Its been an open, transparent, and very thorough process.
So why is this such a big deal?
It means IANA (and ICANN) is now responsible largely to the broader Internet multi-stakeholder community, a community that anyone (and any organisation) can choose to become involved in (and EFA very much has chosen to actively participate, as have many other Internet activists including other civil society organisations, academics, and technologists).
Many in the global community, in light of revelations about mass surveillance, had become unwilling to continue with the US government is such a vital role, and there was resistance from many nations to the US continuing. But equally, there was strong resistance from many in the international community, both diplomatic and technological, to control over the Internet being handed to an inter-governmental organisation, such as a United Nations agency like the International Telecommunications Union.
The US government, which had had a long standing policy goal of eventually letting go of its oversight role, chose to do it in a way that gave them strong control over what the new system would be, and made sure it was an independent, not inter-government, outcome.
Claims by US conservatives that the transition is about 'giving the Internet' are almost the exact opposite of the truth - no one owns the Internet to give it away, but keeping it out of UN control was part of the reason for transition now. Moving to an Internet that is not controlled by any government or group of governments will enable global Internet policy to remain independent and able to keep Internet user concerns a higher priority than the desires of government. Government has a voice of course (represented particularly by ICANNs Government Advisory Committee), but it will be difficult for government to overrule the rights of users of the global Internet.
And that is a very good thing, and a powerful historical moment, to have a whole global communications medium not run directly by governments (as telephones, radio, satellite communications, and other media dating back to the telegraph have been).
Is it without concerns?
Of course not. There have always been accountability concerns about ICANN, and those concerns were heightened by the prospect of the withdrawal of US government oversight. A second huge community process was begun to enhance ICANNs Accountability to compensate, a process that is still ongoing but has already made significant reforms to ICANN, reforms that hopefully mean the organisation is more accountable than it ever has been.
But the Internet has made its foundations a little more independent, and a little more free, and that isn't a bad thing.