highest peak in the world

The summit of Mount Everest is the highest peak on Earth. The Himalayan peak on the border between Tibet and Nepal, is at an altitude of 8,848 meters (29,029 ft).
highest peak in the Western and Southern hemispheres

The summit of Aconcagua mountain, which at 6,960 meters (22,837 feet) is the highest peak in the Western and Southern hemispheres. It is also is the highest mountain outside of Asia. Aconcagua is located in the Andes mountain range, in Argentina.
highest free-standing mountain peak

Mount Kilimanjaro in Tanzania is the highest free-standing mountain (not part of any mountain range) in the world. It is the highest mountain in Africa at 5,895 meters (19,341 ft) above mean sea level. It's an extinct stratovolcano that last erupted around 200,000 years ago.