What is a wormhole and how is it formed?

Could you please elaborate on what exactly a wormhole is and the processes involved in its formation? I'm quite interested in understanding the theoretical aspects of this fascinating concept within the realm of cosmology and quantum physics. How does the concept of a wormhole tie in with the idea of connecting two separate regions of spacetime? Also, could you explain the hypothetical mechanisms that might lead to the creation of such a bridge in the universe? I'm keen to grasp the scientific principles underlying this intriguing theory.