I found this interesting article.
Indians greet each other with namaste. The two palms are placed together in front of the chest and the head bows whilst saying the word namaste. This greeting is for all - people younger than us, of our own age, those older than us, friends and even strangers.
There are five forms of formal traditional greeting enjoined in the shaastras of which namaskaram is one. This is understood as prostration but it actually refers to paying homage as we do today when we greet each other with a namaste. Namaste could be just a casual or formal greeting, a cultural convention or an act of worship. However there is much more to it than meets the eye. In Sanskrit namah + te = namaste. It means - I bow to you - my greetings, salutations or prostration to you. Namaha can also be literally interpreted as "na ma" (not mine). It has a spiritual significance of negating or reducing one’s ego in the presence of another.