The Statement of Functional Expenses tells you how the organization spends its money. You can even find out such nitty gritty details as how much they spent on the phone or on postage. Here you'll find a description of the organization's mission as well as its major activities. Balance Sheets Part IV returns you back to the world of numbers crunching. The Balance Sheets section lets an organization show how well it fared over the course of the year.
Liabilities are an organization's debt.
The Net Assets of Fund Balances reflect whether the organization has more assets than debts or vice versa. In general, an organization's debt shouldn't greatly exceed its assets or it may not be viable in the long-run. Not only does Part V of the 990 show you where some of the money is, it also tells you who's who in the organization. This is where the IRS plays 20 questions with an organization. This section is a little checkpoint to make sure that the organization's income producing activities serve to fulfill its charitable purpose.