The General Epistles are those epistles (letters) in the New Testament written by an author other than Paul. They are:
Notwithstanding liberal scholarship, each epistle specifically states the author and that the author had a specific relationship to Jesus Christ (James and Jude being His half-brothers; Peter and John being His Apostles).
Due to the uncertainty as to whether Paul wrote the Epistle to the Hebrews (since no author is mentioned, unlike the other epistles he wrote), some lists include it in the General Epistles as well.
By definition the list also excludes the four Gospels, the Book of Acts, and the Book of Revelation.