Sometimes, news articles, scientific articles and other works add a small text to correct certain things that were said, but happened to be wrong, so how do you call this type of text we append like that after it was initially published? I am not sure if the definition depends on the content, which in this case are corrections.
If it's to correct errors, then it is an errata. Some would insist that you should only use that if there are multiple errors, and if there's just one error it would be erratum, but that comes from a bizarre insistence of maintaining the grammar of Latin words when used in English - and there is a long, long convention of use in English that the separately-published or added-after-printing item that corrects errors is called an errata.
If it's not just correcting errors, there are various options. Personally, I favour addendum.
Both terms come from Latin, obviously, but they are normal English words now.