The ER=EPR theory was first thought of by Leonard Susskind and Juan Maldacena in the year hole
ER: Einstein-Rosen
EPR: Einstein-Podolsky-Rosen
A wormhole is also known as the Einstein-Rosen bridge (which is ER). Quantum entanglement was found by Einstein-Podolsky-Rosen (which is EPR). Thus, the ER=EPR conjecture states a connection between the two phenomena. It also provides a method to merge quantum mechanics and general relativity finally solving the problem of quantum gravity.
Quantum Entanglement: Two particles are interconnected and share information at 3×1012 m/s. And these particles have opposite spins. If one of the two particles is observed to have spin “up” then the other particle will always have spin “down”.
Wormhole: Wormholes connect two points in space time. An analogy for this is: take a piece of paper draw two points on completely on opposite sides of the paper. The connect those two points by folding the paper and connecting the two sides. That is a how a wormhole works. The ER=EPR conjecture states that both phenomena are caused by the other.
TheTheorists 