What is custom creative templates for DoubleClick for Publishers?

Creative templates for DoubleClick for Publishers (DFP) are predefined creative types that you can use when adding new banners on DFP ad server.

With template-based creatives, you can convert effortlessly simple banners to rich media ads (high CPM ads) and show them in publisher's site via DFP ad server without technical knowledge.

You can read more about custom creative templates for DFP on official pages.