The noun edition mostly relates to publishing and broadcasting. Its main definitions are (1) the entire number of copies of a publication, (2) a version of a publication, (3) a radio or television news program, and (4) the release of any number of like or identical items produced as a set. Addition relates to adding and things that are added. It means (1) the act or process of adding, and (2) something added.
The difference between these words is straightforward, but writers sometimes mix them up—for example:
Ian McShane’s Blackbeard is another welcome edition and here is re-imagined as a necromancer. [Film Shaft]
This latest addition of smarter highways technology is part of the SR 520/I-90 Active Traffic Management Project. [Lake Stevens Journal]
That’s why I’m recommending, in edition to Hoover’s benefit concert on May 19, ACME Gallery’s “Rebuild! Art for Tornado Relief “ fundraiser on Thursday. [Birmingham Weekly]
Addition and edition may occasionally come dangerously close together in meaning, as in the second example above. Just remember that addition is often (though not always) followed by the preposition to, and edition is almost always followed by of.
These writers use addition correctly:
The package will see the addition of four boats to MCS’ existing fleet of nine support vessels. [BBC News]
In addition, 12.5 million people, or 68 per cent of Aussies, say they know people who are finding it difficult to pay for basic necessities. [Sydney Morning Herald]
And these writers use edition well:
For its 25th edition, the world-music event will move its outdoor gathering place from its former location to the parterre of Quartier des spectacles. [Montreal Gazette]
The special edition of the book will be available only for Amazon Kindle e-readers and will sell for $9.99. [Los Angeles Times]