The period was called the Grand Unification Epoch
It was the way the universe functioned after the Planck Epoch which started at about 10^−43seconds after the Big Bang happened. The planck epoch is how the universe is perceived to have been before the big bang occurred. It lasted until the 10^−36 seconds after the Big Bang which in layman terms seems like a short time, unperceivable, but was extremely important.