| The above writeup does describe the physical aspect of greeting someone while in Korea very well, however there is usually more too it.
"Submissiveness to authority - parents, elders, and superiors" -- this phrase originated back to the teachings of Confucius in 14th century and is still regarded as an important custom. Respect for elders is crucial. You will find that in Korea age is an important factor in a relationship. Whatever the older person says, goes! While the whole concept is a strict Korean rule, you are not obliged to follow it. However, you would be regarded as a polite and well-mannered person if you did. It is expected that a young person gives up their seat on a bus or train for an elder, although some youth do not see it as necessary. The upside to this concept is that when you go out to eat with someone, it is custom for the older person to pay for the meal. They will also look out for the younger person and share their knowledge.
If you are meeting someone for the first time, it is a good idea to give a detailed introduction about yourself. Tell them about your job, nationality etc. Koreans tend to be curious about foreigners, so satisfy their curiousity.
Upon entering a Korean home, remove your shoes.
Use two hands when shaking hands with an elder.
When accepting a gift from an elder, use two hands.
Think of the Korean bow as a substitute to waving. Remember to bow when saying hello, and again when saying goodbye.
Koreans also tend to use an informal version of the language when talking to well known friends or younger people. "An nyung hah sae yo" is used when speaking to an elder, yet if you are conversing with a friend you can abbreviate the greeting to simply "an nyung". | 
