Asia is bounded by the Pacific Ocean to the east, by Australia to the southeast, and by the Indian Ocean to the south. It's bordered by the Red Sea to the southwest, by Europe and the Urals to the west, and by the Arctic Ocean to the north.
Central Asia (Afghanistan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan)
East Asia (China (which includes Hong Kong and Macau), Japan, Mongolia, North Korea, South Korea, Taiwan)
South Asia (Bangladesh, Bhutan, India, Tibet, Maldives, Nepal, Pakistan, Sri Lanka)
Southeast Asia (Brunei, Cambodia, East Timor, Indonesia, Laos, Malaysia, Myanmar (Burma), Philippines, Singapore, Thailand, Vietnam)
Not included in Asia are:
Middle East (Bahrain, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, Turkey, United Arab Emirates, Yemen, Palestinian Territories)
Russia and the Caucasus (Azerbaijan, Armenia, Georgia, Russia)