There are a number of different types of reverse mortgages and a number of different reason to use one. All reverse mortgages have a few things in common.
You can use the money any way you want;
ALL reverse mortgages are non-recourse loans. This means that the only source of repayment is the real estate - no other assets are used to repay the loan - ever
No monthly payments are required
The money you take-out is generally tax-free
You can borrow a few thousand dollars or as much as $4 million

With a fixed rate reverse mortgage all of the available proceeds are paid at once. This is a good option for older borrowers, in their 80s or 90s, who have great immediate financial need. It is a less attractive option for borrowers in their 60 and 70, and even 80s, who have the ability to space-out their receipt of money.
The most typical reverse mortgage and for very good reason. Borrowers can take only as much as they need at closing and, whatever they qualify for and don't yet need, will be available in a line of credit. This line of credit grows at the same interest rate as the mortgage offering an effective hedge against inflation. Unlike a Home Equity Line of Credit from your bank there is never any payment required, the credit line increases monthly and can not be lowered nor cancelled, unlike a Home Equity Line from your bank,
This option is great for condos that are not FHA approved and for larger loan amounts, up to $4 million and even more depending on the situation. It also features lower closing costs. The monimum age requirement is only 55 years old as opposed to 62 for the FHA products.