经 (jīng) = the canonical classics themselves (
《诗》 《书》 《易》 《礼》 《春秋》).
传 (zhuàn, NOT chuán here) = the authoritative commentaries that accompany them, for example
《左传》,
《公羊传》, and
《谷梁传》 attached to the Spring and Autumn Annals
《春秋》.
经传 together names the entire scholarly canon.