The Second Epistle of John is a book of the New Testament attributed to John the Evangelist, traditionally thought to be the author of the other two epistles of John, and the Gospel of John (though this is disputed). Most modern scholars believe this is not John the Apostle, but in general there is no consensus as to the identity of this person or group.
Second John and Third John are the two shortest books in the Bible. The shortest book in the English language is different depending on which translation (version) one reads. For example, in the New International Version 2 John is the shortest book with only 302 words but in the King James Version (Authorized Version) 3 John is the shortest with only 295 words. However, Second John has the fewest verses in the Bible with only 1 chapter made up of only 13 verses.