DPC stands for damp proof course, is made of concrete 1:2:4 and is maximum 2 to 3 inches thick. As its name suggests, it is used for prevention from earth/soil moisture. This method is in practice in brick structure houses and is effective if both horizontal and vertical DPCs are properly placed (I have already posted a detailed article on it in blogs section). However plinth beam at any day will always remain superior to DPC, plinth beam is made in RCC, reinforced cement concrete and most of the time it’s size is 9″x 12″. It is the best method to prevent moisture and seepage and secondly it acts as a tie beam to0 and holds the foundations together giving much more strength. All frame structure houses/buildings have plinth beams instead of DPC. In my opinion, plinth beams should be enforced as a normal practice instead of DPC even in brick structure houses. Once you have the plinth beam, there is 0% change for the seepage or moisture to travel upwards, however in case of DPC, a very minor defect or even in case of no defect, there always remain a chance for seepage or moisture to travel towards walls.
We just recently completed a 5 marla grey structure where plinth beam was used for damp proofing instead of DPC and it costed us around 65 Rs/sqft more. (complete double story house with ground floor first floor and 150 sqft mumtee, total covered area was 1850 sqfts).