There are three types of Mountains: Mountains of Accumulations or Volcanic Mountains that were formed by the eruption of volcanoes, Folded Mountains that were developed by the layers of Earth's crust, and Mountain Erosion which are formed by the erosion of rocks.
12% of the world's people live in the mountains.
FUN FACT: New Zealand has the world's longest mountain name. It is "Taumatawhakatangihangakoauauotamateapokaiwhenuakitanatahu". It is a Maori expression and translated into English it means "the place where Tmatea, the man with the big knees, who slid, climbed, and swallowed mountains, known as 'landeater' played his nose flute to his loved one."