A CEO (Chief executive officer) is responsible for all the companies activity including human resources, management, production, services, sales, and Tax rules. They make decisions and take responsibility for those decisions and their outcomes, this is the biggest part of their job.
The decision about the company’s future to which the company is headed. They lead, they guide, they set the culture of a company. They make sure the company doesn’t run out of money, it’s the CEO’s job to ensure the company has enough capital.
Their work is to reduce volatility (or risk) so that company can become more stable and attractive to business. Also, a CEO’s job is to take on other jobs if needed to fill the gap temporarily. This can happen during startup, downsizing, or some other changes.