To cut it short, DFP does the management, delivery and measurement of your ads. DoubleClick for Publishers is a constituent part of DoubleClick Ad Exchange which allows you to make connections with a great number of Google AdWords advertisers, with a variety of ad networks and trading desks that are competing for your inventory. By signing up for DFP, you will be able to manage your whole advertising by just one single network because that’s what subscription for DFP means: you get a certain network for the management of your advertisements. more at http://www.adopsguys.com/about-us/blog/