The concept of "before" the Big Bang is not well-defined within the current understanding of physics. The Big Bang is the prevailing cosmological model that describes the early development and expansion of the universe. It suggests that the universe began as a singularity, an extremely hot and dense point, and has been expanding ever since.
According to the Big Bang theory, time and space as we know them also originated from the singularity. Therefore, it is not meaningful to talk about what existed before the Big Bang in the traditional sense of time and space. The Big Bang marks the beginning of the universe as we know it, and any events or conditions prior to it are currently beyond the realm of scientific observation and understanding.
Speculations and theoretical frameworks, such as the concept of a multiverse or cyclic universes, have been proposed to explore the possibility of events before the Big Bang. However, these ideas are still highly speculative and not yet supported by empirical evidence. The nature of what, if anything, existed before the Big Bang remains an open question in cosmology and theoretical physics.