As you know we have many kinds of greeting and you need it for communicating with people all over the world and people who live in different countries have different ways of greeting. Start a greeting is a best way to know about their culture.
I will mention some kinds of it.
One of them is cheek kissing which is different in each country and it's more common in Europe and Latin America than North America, except for Miami and Quebec.
However, the countries in South East Asia with Muslim or Hindu culture are much harder to think that they kiss when they say to greeting than Asian countries like Japan, Korea and China. Because, kissing between men and women is not socially acceptable way of greeting and also is considered offensive way for them through their religion.
In Japan people bow when they want to greet and in some countries they hug each other.
What's your opinion ?why we have different kinds of greeting?!