Hola Ryan

"Era" and "Fue" both come from the infinitive "ser" (to be) - they both mean "he/she was". Era is the imperfect tense and Fue is the simple past tense. We use one or the other depending on what we want to convey in Spanish. The Imperfect is usually for when you want to say "he/she used to be..." or simply want to be more descriptive about the past. The simple past would be used for actions that we consider as completed, where we can see an end of that action. 

There is a specific lesson about this. Have a look here.

I hope it helps.

Inma