Jesus in the Talmud
In the first few centuries CE, there were many sects of Judaism (such as Pharisees, Essenes, and Sadducees) each claiming to be the correct faith. Some scholars treat Christianity, during that era, referred to as Early Christianity, as simply one of many sects of Judaism. Some sects wrote polemics advocating their position, and occasionally disparaging rival sects. Some scholars view the depictions of Jesus in the Talmud as a manifestation of those inter-sect rivalries – thus the depictions can be read as polemics by the rabbinic authors of the Talmud which indirectly criticized the rival sect (Christianity), which was growing and becoming more dominant.
Heresy in Orthodox Judaism
The Greek term ἁίρεσις originally denoted "division," "sect," "religious" or "philosophical party," and is applied by Josephus to the three Jewish sects: Sadducees, Pharisees, and Essenes. The specific rabbinical term for heresies, or religious divisions due to an illegitimate spirit, is מינים ("minim") (lit. "kinds [of belief]"; the singular מין ("min") (literally, "a kind") for heretic or Gnostic is coined idiomatically, like "goy" and "`Am ha-aretz"). An alternative term, אפיקורוס (Apiqoros/Apikoros), which may have a different status, and is often used for apostates who turned towards agnosticism or atheism, is derived from Epicurus and the philosophy of Epicureanism.