King James Version
The King James Version is an English language translation of the Bible, first completely published in 1611. The Bible was translated at the behest of King James I of England (VI of Scotland). Translators used the original Greek and Hebrew texts, but also consulted some previous English translations, particularly William Tyndale's translation (1525-34). The text of the King James Bible remains remarkably similar to Tyndale's translation.
A minority of Christians in English-speaking countries hold that the King James Version is the only acceptable English translation. This is often referred to as the "KJV-only movement". They hold that God inspired the translation in the same way he inspired the original text, in order to ensure a reliable transmission of his Word to the English speaking world. Nevertheless there are errors in the translation, such as calling the Jewish passover "Easter" in Acts 12:4.
The New King James Version is a modern translation using the same source texts as the King James Version and attempting to preserve the style of the KJV but in modern language. The 21st Century King James Version is a minor revision of the King James Version in which only the most archaic English words are replaced with their modern equivalents.