The Chief Financial officer is responsible for all the planning and implementing of all the financial activities running in a particular company. They also analyze the financial strengths and weaknesses of the company and help them to act accordingly.
The third thing a CFO does is help earn the company earn the highest possible risk-adjusted return on assets and return on capital. This is where the financial planning and analysis comes into play- which is done by CFO.
If the company has a corporate development team, they also play a big part in creating (or attempting to create) optimal investment returns for the business
CFO has certain other job opportunities too such as investment banker, financial analyst, finance manager, finance director, etc.