Higher-education experts say the Obama administration has proposed the broadest overhaul of federal college aid programs in decades. But for all the focus on the size of the budget, it has been hard to tell just what this means for students and their families.

One problem is that whatever the president proposes, Congress actually holds the purse strings. So there is no way to know just what aid will really be available down the road. But based on what administration officials have said, here is a summary of how the budget as proposed would affect funds available to help pay for college.

The first important thing to understand is that the proposed benefits will not be available until July 1, 2010 — more than a year from now.