A "durable power of attorney for finances" is a key estate planning document. In it, you give someone you trust authority over your assets, just in case someday you are unable to handle them yourself because of illness or injury. (That's why the document is called a "durable" power of attorney--a regular non-durable power of attorney automatically terminates if you become incapacitated.)
A financial DPOA can be of great help to family members if someone becomes unable to manage day-to-day financial matters, like paying bills. For example, if you were incapacitated, your spouse might need access to your checking account to pay the mortgage. Without a DPOA for finances, a court order would be necessary.
Even if you're in great health, it's smart to create a durable power of attorney for finances. It's very unlikely that the document will ever be used. But if you were suddenly injured or taken seriously ill, the DPOA would let your family take care of financial matters without the expense and unpleasantness of going to court to prove you were incapacitated.
Each state has its own laws that set out what makes a financial DPOA valid. You can find your state's rules here, and you'll probably be able to create your document without hiring a lawyer.
Select your state to learn about your state's laws.