When you meet someone, it is normal courtesy to greet them and in all cultures it is customary to greet them when coming and going. It is nice to see how the Norwegian way of greeting has changed in the 38 years I have lived here. Back then there was no cuddling or hugging classmates/colleagues etc. This is clearly something that has come about in the last 25 years. The formal thing is to shake hands and when hands meet, it gives a good energy/start to a meeting. In Asia, there is more emotion and respect associated with greetings, you bow in respect for the other person and especially if the other person is older. Namaste or namaskar means the light in me greets the light in you, as we believe that we are all "light energies". It sounds a bit nice in English I think; the light in me bows to the light in you . 
We place both palms against each other at chest height and bow our heads slightly as the word namaste is pronounced. Several of you who practice yoga have probably heard it and used it without fully knowing what it means. There is another aspect to this. The palms have a lot of nerve endings - something that medical science has also discovered over time. We communicate a lot with our hands and in yoga, mudras (hand positions) are a whole science. Just by holding your hands in certain ways, your entire system functions in different ways. The moment you place your hands together, your "duality" of what you like and don't like, your demands and objections, are flattened. The energies work as one. When we bow our heads, you lower your ego and accept the other as they are without thinking about positive or negative qualities in the other person and show the ability to unite. The ability to recognize the energy in the person you meet. It is incredibly deep and beautiful, I think. NAMASTE!