An important difference between the federal government’s budget and a personal budget is that only the government’s budget involves

A personal budget allocates future personal income towards expenses, savings and debt repayment, whereas the government's budget gets revenue by collecting taxes. For example, a federal government collects: 1.Federal taxes (
individual and corporate taxes, capital gains tax, excise (i.e. manufacturing) taxes, social security tax, inheritance and estate taxes) 2.Borrowings and 3.
User charges
I hope this helps, I don't know what specifically does the gap refer to!