Arrowverse
The "Arrowverse", also known as the CW Multiverse or simply CWverse, is a group of  television programs that take place in a shared universe. It is based on characters that appear in publications by DC Comics. The shared multiverse is like the DC universe in these comic books. The programs have had crossover stories, settings and characters from other series in the group. The group began with the series Arrow in 2012. Over time, it added The Flash, Supergirl, DC's Legends of Tomorrow, Batwoman and others.