Salute originated from maritime hegemony about 400 years ago. At that time, Britain, the Netherlands and other countries as allies already had navies and naval gunboats, and they joined forces against Spain. On one occasion, a British naval gunboat carried out an order to go to a port. When passing an island, it found a warship moored opposite. The British soldiers were very nervous at once and didn't know if they were enemies. If it is the enemy, if you don't attack before the enemy, you will miss the fighter plane; If you are not the enemy, you will hurt your friends by mistake.
The officer in charge of the pilot decided to shoot into the air to test the other side's intentions. So the soldiers raised their guns and fired two shells into the sky.
As soon as the gunfire stopped, the other side also fired two shells into the sky, showing that the other side was not hostile. So the British gunboat sailed past with confidence. It turned out that the other warship was the fleet of the allied Dutch navy, and the soldiers of the two ships exchanged greetings with smiles.
This is the original meaning of salute. Later, many countries fired guns into the air as a ceremony to welcome the head of state. Then, why is the salute to greet the head of state 2 1? It is said that this stems from a small error. At that time, German citizens in augsburg welcomed a head of state who returned triumphantly from the front. For the sake of solemnity, they decided to salute 20 times.
However, the officer in charge of shooting got confused after counting and fired 2 1. I didn't expect to get the right number. People think that 2 1 is better, so the tradition of 2 1 cannon has been inherited to this day.