All worm holes are black holes, but not all black holes are worm holes. The complete Schwarzschild geometry consists of a black hole, a white hole, and two Universes connected at their horizons by a wormhole. The negative square root solution inside the horizon represents a white hole. Where the black holes swallow things irretrievably, white holes spit them out. It is because white hole is a black hole, running backwards in time. White holes cannot exist since they break the second law of thermodynamics. But general relativity is time symmetric. It doesn't "know" about the second law of thermodynamics as well as it doesn't know about which way cause and effect go. The negative square root solution outside the horizon represents another Universe. The wormhole joining the two separate Universes is known as the Einstein-Rosen bridge.
mmm didnt know that Who sais LZ is mindlessly gaming entertainment? general laws of physics are considered not to be in order inside a blackhole, so makes sence