The Confucian Five Classics comprise five books: the Classic of Changes, Classic of Documents, Classic of Poetry, Book of Rites, and Spring and Autumn Annals.
These works were treated as foundational sources for Confucian learning, especially during and after the Han dynasty. They cover divination and cosmology, government documents, poetry, ritual practice, and historical interpretation. Their contents and editions changed over time, so the phrase refers to a traditional group rather than five completely uniform manuscripts.
The Five Classics are different from the Four Books. The Four Books became especially important in later Neo-Confucian education and contain the Great Learning, Doctrine of the Mean, Analects, and Mencius. The Five Classics are generally regarded as older and more varied in subject matter.
The number five is therefore a classification of the canon, not a claim that the tradition had only five important writings.