If you mean the in game scrolls

The Elder Scrolls (Kelle in the Dragon Language), also called the Aedric Prophecies (though the accuracy of that term is often disputed), are scrolls of unknown origin and number which simultaneously archive both past and future events. The number of the Scrolls is unknown not because of their immense quantity, but because the number itself is unknowable, as the Scrolls "do not exist in countable form". They are fragments of creation from outside time itself, and their use in divining prophecies is but a small part of their power. They simultaneously do not exist, yet always have existed

There is a further theory on what the Elder Scrolls actually represent.

If you mean the game series then they were made by Bethesda and there are currently 13 titles in the series including spin offs