What are the two major mountain systems that include most of Earth’s mountain ranges?

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A car drives along the Trans-Canada Highway with Mount Sir Donald's sharp, snow-capped peak rising above forested slopes in the Selkirk Mountains, British Columbia. — mountain Mount Sir Donald in the Selkirk Mountains, British Columbia, looms above a segment of the Trans-Canada Highway.

Most of Earth’s mountain ranges are part of two major, nearly continuous mountain systems that generally mark the boundaries where lithospheric plates converge:1

The Circum-Pacific System: A nearly continuous chain of volcanoes and mountain ranges that surrounds the Pacific basin.1
The Alpine-Himalayan (or Tethyan) System: A chain that stretches from Morocco in North Africa through Europe, Turkey, and Iran, continuing through the Himalayas to Southeast Asia.1

Most mountain ranges that do not fall into these two systems are classified as residual mountains, which originated from ancient continental collisions that occurred hundreds of millions of years ago.1