It is polite to say hello when you meet others,and in different places ,the greeting is different because of different culture .
A friend from Venezuela usually say "How are you ,my friend" . In our country ,people usually say "Where are you going " .
What about you ?
It's really an interesting question. In my opinion, greetings are something that we cannot learn from textbooks, since it's influenced by culture and personality. The best way to be polite is to learn the most common greetings from local people. I came to the states last September, and only a few days later, I noticed that people greeted in a diffetent way from what I learned at school. Usually, they say: hello/hi, how are you doing/what's up? The answers can be: good, great, not bad. When leaving, people always say: have a good day/night, good day. I'm not sure whether it's because I'm studying in school, people here are friendly and like greetings, they greet to each other, even to the strangers.
WOW ,After reading all of your comments , I think it is amazing .You are right ,The greeting is different not only because of culture ,but also depends on personal style .
Paul ,you said it is confusing ,I can understand. "Alright ? " is a question ."All right " is a positive sentence .
We didn't know each other before ,so it is the first time we meet here .
Hi, Nice to meet you all !
It also depends on personal style. If I meet a stranger for the first time I will normally say "Hi, nice to meet you". If it's a friend or family member it's usually "hey, how's it going?" Or just "hey". This is pretty common across most of Canada. In the province of Newfoundland people will sometimes say "how's she going?"
You could also say 'Alright, how's it going? or 'Hi, how's it going?'. 'How's it going?' is an informal way to ask 'How are you?'.
In the UK, where I live anyway when people meet their friends they usually say 'Alright?' or 'Alright mate?', which combines a greeting with asking how someone is. Efficient :)
You can respond to this with 'all right' (pronounced the same as 'alright', confusing I know) or 'not too bad' to show that you are doing OK.
In actual fact I don't think I say hello very often unless I'm answering the telephone, or meeting someone in a formal situation. Even then its often fine to say 'hi' instead of hello.