Era
Part of speech: noun
Definition: A time period of indeterminate length, generally more than one year.
Example sentence: We should not be afraid to go into a new era, to leave the old beyond.
Epoch
Part of speech: noun
Definition: A particular period of history, especially one considered remarkable or noteworthy.A notable event which marks the beginning of such a period.A precise instant of time that is used as a reference point.A precise instant of time that is used as a reference point (e.g. January 1, 1970, 00:00:00 UTC).
Example sentence: In all the areas within which the spiritual life of humanity is at work, the historical epoch wherein fate has placed us is an epoch of stupendous happenings.