Well, it depends. It may be a simple way of saying here I am! or hey, listen to me! A handshake is basically an agreement that the participants aren't going to attack each other for the duration of the meeting. A bow may be a quite precisely formulated show of respect.
But you have to be careful, because you may be getting more than you bargain for when you greet someone.
The Maori hongi, which involves two people pressing their foreheads and noses together while exchanging breath, is a formal greeting and performs some of the functions as a handshake.
But there are snags to the hongi. For a start, there's a traditional feeling that exchanging breath has an exchanging-soul aspect to it, which one doesn't normally expect with a handshake (unless you're accepting a job at a major investment bank); and, as well, the performance of the hongi means, technically that you are Tangata whenua, one of the people of the land.
This is, of course, a huge privilege. It does come with minor disadvantages, though, such as a duty to help out in any imminent battles and the getting in of the harvest.
It gives a whole new meaning to keep your nose out of trouble, doesn't it?
Word To Use Today: hongi. This word is Māori, of course.