The Cash on Hand number on the Budget Analysis table is calculated by subtracting your total number of actual disbursements from your total number of actual contributions. This Cash on Hand number represents what your cash on hand is right now.
The Cash on Hand Over Time Graph number will show you a projection of your cash on hand by the end of the day today. In other words, the number you see here is what you should expect your cash on hand to be at the end of the day today if you were to spend everything you have budgeted today, and if you raise everything you have projected to raise today.