According to the agreed text, the Digital Market Act (DMA) is a “targeted set of legal obligations (. . .) to ensure contestable and fair digital markets featuring the presence of gatekeepers.”
In their recent article, Sean-Paul Brankin and Pat Treacy outline the “challenges for the regulator as well as the regulated” that may result from an act that is extraordinary in its ambition and complexity.
As well as the challenges, this piece discusses both why we have the DMA and how it works including objectives, obligations and enforcement powers.
 DMA, supra, recital 8.