It stands for "Decentralized Hive Fund"
It's the blockchain (Hive)'s fund for projects. If a project has community support and is doing good things for the chain, they can ask for funding and the community can vote it into funding
It can be a bit political. INLEO in my opinion (obviously biased) deserves to be funded as we lead innovation on Hive and onboard the most users per year to the chain
You can read & vote for the proposal via a Hive-focused UI called PeakD: https://peakd.com/me/proposals/332
If it supports this amazing project then there's no need to read.
I hit the support button. Is that all?