>>514909435
Original Judaism was centered around the Temple. The Priests of the temple took care of the holy of holies or some shit. All significant religious practices were through the temple. They did shit like sacrifices and all that old bronze age shit.

Then, in 66 AD, the Romans sacked Jerusalem and destroyed the 2nd temple. The jews were scattered and a lot went to Babylon. In Babylon, they were struggling because they didn't have the temple and couldn't perform their religious rites.

Then, the elders wrote the Talmud. This is supposed to be the outline of the temple rites preserved and new laws/rules to guide them as a people that lost their priesthood, land, and government.
Groups of jews will be "guided by an elder" which is known as a Rabbi. This guy keeps the knowledge and traditions alive sans temple.