This question is a bit ambiguous. However, this is what I found.
This question is related to Egress and Ingress. The answer in this case is
Egress. Basically, Egress is another name for exit and is used in very many situations to mean leave. Thus, in this example, Egress may mean flow of fans out of a stadium. Typically, it is an opening or a path for an exit. On the other hand, Ingress means flow of fans into the stadium and the roads that lead to the stadium.