"Himalaya" is a Sanskrit word which literally means "abode of snow" a term coined by people who travelled in these mountains in ancient times.
The Himalayas began forming around 50-30 million years ago when the then separated continent of India collided with the Eurasian plate. This mountain range is relatively young and still experiencing uplift as the Indian continent moves northward at about 2-3 centimeters per year, making the Himalayas the tallest mountain range on Earth.
See plate tectonics.