Service Financial Management
Service financial management is a general management practice in ITIL 4 that's just for your general knowledge as it's not covered on the foundation exam. This practice is focused on supporting the organization strategies and plans for service management. It does this by ensuring that the organization's financial resources and their investments are being used effectively. So if you've ever decided to make the recommendation to your boss that you need to go and buy X, Y, Z system or X, Y, Z software product and install it in your system, at some point, he will probably asked you how much that idea would cost and if it would be worth it.
Service Financial Management is that whole back-end process to verify that you have enough money to buy the things that you want to get and that what you want to get is going to give the organization a good return on the investment so that the capital is actually used in the most effective way. There's a ton of things that you can buy with your organization's money. The thing though, is you want to make sure you're doing it responsibly and that you're going to get the best bang for your organization's buck.
Service Financial Management is all of those back-end things that the accountants are going to do and the business analysts are going to do to ensure that your company remains financially solvent and that you're able to continue operating because you have money to pay your employees, pay for your services, pay for your contracts, and keep the business afloat.