Board Thread:Oblivion/@comment-27279223-20151124142818/@comment-6881629-20151124210334

You use the spells you already know to create more powerful or combined versions of them. Theres some examples on the page here but it also allows you make spells like Dragonborn's Chaos enchantment one single spell that does fire, frost and shock damage at the same time. Or just to make spells with names you prefer to the default ones. If your skill in the magic school is high you can make some that do ridiculous damage too.