CEO vs COO
CEO and COO are both top-level C-suite roles, but they sit at different points in the hierarchy. The CEO holds the highest-ranking position in the company; the COO sits just below, reporting directly to the CEO.
The CEO is essentially the face of the company, accountable for its successes and its failures alike, and responsible for the big corporate decisions along with managing the company’s overall operations and resources. The COO’s job is narrower and more operational: day-to-day administration, things like marketing and sales, HR, R&D, production, and whatever else keeps the business running on a daily basis.
One other difference worth noting: CEOs often go by other titles too, Managing Director, Chief Executive, President, depending on the company. COO, on the other hand, pretty much only goes by COO.