A salute is usually a formal hand gesture or other action used to display respect in military situations. Salutes are primarily associated with the military and law enforcement, but many civilian organizations, such as Girl Guides, Boy Scouts and the Salvation Army use formal salutes. Ordinary civilians also salute informally to greet or acknowledge the presence of another person, such as a tip of the hat or a hand wave to a friend or neighbour.
Throughout history, military organizations have used many methods to perform salutes. Depending on the situation a salute could be a hand or body gesture, cannon or rifle shots, hoisting of flags, removing headgear, or other means of showing respect or deference.
According to historical reconstruction, the ancient Roman military salute (salutatio militaris) was analogous to the current military salute. According to some modern military manuals, the modern Western salute originated in France when knights greeted each other to show friendly intentions by raising their visors to show their faces. Others also note that the raising of one's visor was a way to identify oneself saying "This is who I am, and I am not afraid." Medieval visors were, to this end, equipped with a protruding spike that allowed the visor to be raised using a saluting motion.
Also to show a sign of peace, that they are not carrying a weapon [in their right hand].
The US Army Quartermaster School provides another explanation of the origin of the hand salute: that it was a long-established military courtesy for subordinates to remove their headgear in the presence of superiors. As late as the American Revolution, a British Army soldier saluted by removing his hat. With the advent of increasingly cumbersome headgear in the 18th and 19th centuries, the act of removing one's hat was gradually converted into the simpler gesture of grasping or touching the visor and issuing a courteous salutation.
As early as 1745, a British order book stated that: "The men are ordered not to pull off their hats when they pass an officer, or to speak to them, but only to clap up their hands to their hats and bow as they pass.