Draconic

The language of dragons and magic, Draconic is one of the Six Eternal Languages. It is at once harsh and soft, flowing and staccato; when spoken correctly, it sounds as if two or even three octaves are sounding together in unison. And regardless of the speaker, Draconic always carries a sense of pure, raw power. 
The various species of dragons have their own dialects but one can usually understand the other (all besides the Void Dragon), while the form used for arcane spells is also known as proto-Draconic and is as ageless as any of the Six.
The Draconic Script is the written form of the Draconic language and that used in arcane scrolls, spellbooks, and sigils.