From publisher blurb:
Some dragons utilize warlock servants as a means of collecting additional treasure for their hoards, while others may be bound to a dragon who imprinted upon them after hatching, a magical defense mechanism meant to defend wyrmlings from harm until they mature into the ferocious creatures of legend. Others who wield draconic power may use this pact as a means of forming an apprenticeship, granting their student a fraction of this magic until they prove themselves capable of using it independently.
Building off of the existing Fifth Edition rules to build a warlock character, the Dragonbound patron grants warlocks a portion of draconic power through intense elemental spells and martial prowess by suppressing others' magic around them. This PDF also includes two alternative pact boons, compatible with any warlock character.