Exemplar is an eternal format that encompasses Eighth Edition and forward (the same as Modern). The defining restriction for deckbuilding is that you can only build your deck out of cards that were once in a standard format together. For example, your deck can contain Archangel Avacyn with either Hangarback Walker or Walking Ballista, but not both, because Hangarback Walker and Walking Ballista were never in the same standard format together.
This means that you will get to see many of the great standard decks battling against each other, but tuned to beat a meta filled with such archetypes. So UB Faeries might play Faerie Macabre in its sideboard because it can answer Unburial Rites or Goryo's Vengeance, even though it wouldn't make much sense its native Time Spiral-Lorwyn standard.
Here is a list of all of the eras:
- Eighth Edition - Mirrodin Block - Kamigawa Block
- Mirrodin Block - Kamigawa Block - Ninth Edition
- Kamigawa Block - Ninth Edition - Ravnica Block - Coldsnap
- Ninth Edition - Ravnica Block - Coldsnap - Time Spiral Block
- Ravnica Block - Coldsnap - Time Spiral Block - Tenth Edition
- Coldsnap - Time Spiral Block - Tenth Edition - Lorwyn Block
- Tenth Edition - Lorwyn Block - Alara Block
- Lorwyn Block - Alara Block - M10
- Alara Block - M10 - Zendikar Block - M11
- Zendikar Block - M11 - Scars of Mirrodin Block - M12
- Scars of Mirrodin Block - M12 - Innistrad Block - M13
- Innistrad Block - M13 - Return to Ravnica Block - M14
- Return to Ravnica Block - M14 - Theros Block - M15
- Theros Block - M15 - Khans of Tarkir Block - Magic Origins
- Khans of Tarkir Block - Magic Origins - Battle for Zendikar Block
- Dragons of Tarkir - Magic Origins - Battle for Zendikar Block - Shadows over Innistrad Block
- Battle for Zendikar Block - Shadows over Innistrad Block - Kaladesh Block - Amonkhet Block
The banned list consists of any cards that were ever banned during their tenure in standard: