Cho Oyu is a sub-peak of Mount Everest, meaning it's a secondary peak in the same mountain range, but not the highest point. It's also considered a tectonic mountain, formed by the collision of the Indian and Eurasian tectonic plates.

While Cho Oyu is often referred to as a Himalayan mountain, it's more specifically a peak in the Mahalangur Himal sub-range, which is part of the larger Himalayan range.