southeast asia or southeastern asia is a subregion of asia, consisting of the countries that are geographically south of china, east of india, west of new guinea and north of australia.
the region lies near the intersection of geological plates, with heavy seismic and volcanic activity. southeast asia consists of two geographic regions:
maritime southeast asia, comprising indonesia, east malaysia, singapore, philippines, east timor, brunie, cocos (keeling) islands, and christmas island.
mainland southeast asia, also known historically as indochina, comprising cambodia, laos, myanmar (burma), thailand, vietnam and west malaysia
source : https://en.wikipedia.org/wiki/Southeast_Asia