I found this on the official website:

Capture an Elder Scroll, protect it, and return it to your alliance’s stronghold to wield its power and gain bonuses.
Elder Scrolls are artifacts of immense power that aid an alliance in the ongoing battle to control Tamriel by conferring bonuses to every member of that alliance. Each alliance has a special stronghold in Cyrodiil where their Elder Scrolls are kept and protected – but enemy alliances can break in and take them if they are not guarded properly. Once access is gained and a Scroll taken, it must be taken back across Cyrodiil and placed in the alliance’s stronghold. Only then are the bonuses of the Scroll bestowed upon all the members of that alliance.

Link: http://elderscrollsonline.com/en/game-guide/the-alliance-war

So I guess its the exact same as DAoC only in that game you had relics that gave realm bonuses, those bonuses were also used in the PvE part of the game in DAoC.