I was wondering whether the EL replaces ES as a framework for providing services for enterprise apps,
or it supplements it. I know nothing of either of these technologies, but from just looking at their feature set,
I noticed that they don't exactly share the same features, for example ES offers services such as just-in-time activation
and object pooling that I don't see in EL. I need to know if I should learn both these technologies or just one,
so I could better plan my schedule.