Prologue

Wikipedia please~

A prologue or prolog (Greek πρόλογος prologos, from the word pro (before) and lógos, word) is an opening to a story that establishes the setting and gives background details, often some earlier story that ties into the main one, and other miscellaneous information. 

Having a prologue isn't necessary. You can have it or not. They can be long or short. It's all up the writer and what you feel what is right to write. But, please I beg you this, if you write a prologue and you believe your story is dull to begin with or not, write the most interesting scene that actually counts.