Greeting, salutation, salute denote the ceremonial words or acts of one who meets, welcomes, or formally addresses another.
Greeting is the ordinary term which carries no suggestion of formality and no implication of inferiority in the one who greets or of superiority in the one who is greeted. On the contrary, the term usually suggests friendliness or goodwill or lack of concern for social or official inequalities.
Salutation applies to a more or less formal phrase, gesture, or ceremonial act whereby one greets another; specifically it applies to such phrases as the conventional “How do you do” or the familiar “Hello,” or to the words of a letter with which the writer first directly addresses his correspondent, or to such acts as a kiss, an embrace, or a bow.
Salute is the only one of these words that applies only to gestures determined by convention or to ceremonial acts; though it seldom applies to a speech, it may be used when to the gesture or act a word or two is added.