he 'wai' is a prayer like gesture which is perfomed with a slight bow. It's widely used in Thailand as a standard greeting, and also when apologising, saying thanks and to show respect. Thai people frequently wai towards a Buddha image when passing by one, sometimes even while driving! If there's a perceived difference in status between two people perfoming the wai, then it is usually the junior or 'lower status' person who will wai first. For instance, a student will wai the teacher first, and not the other way around. The more senior will then usually 'wai' back