The author identified himself as Jude the brother of James. Both Jude and James were half-brothers of Jesus. It is unknown whether this letter was intended for a specific church.
Jude wrote this letter to warn believers against false teachers. Jude often referred to the Old Testament. This may suggest that Jude was writing to a Jewish Christian audience. This letter and 2 Peter have similar content. They both speak about angels, Sodom and Gomorrah, and false teachers.
Translators may choose to call this book by its traditional title, "Jude." Or they may choose a clearer title, such as "The Letter from Jude" or "The Letter Jude Wrote." (See: [[rc://en/ta/man/jit/translate-names]])
It is possible that the people Jude spoke against were those who would become known as Gnostics. These teachers distorted the teachings of scripture for their own gain. They lived in immoral ways and taught others to do the same.