Final answer:
Military personnel render the salute while under arms by bringing their right hand to the brim of their hat or raised to the brow, depending on their uniform, as a sign of respect and recognition of superior authority.
Step-by-step explanation:
Military personnel render the salute while under arms by bringing their right hand to the brim of their hat or raised to the brow, depending on their uniform. The salute is a sign of respect and recognition of superior authority. It is an outward symbol of military discipline and professionalism. For example, in the United States military, when a soldier is wearing a hat, they would extend their right hand upward in a crisp motion with the fingertips touching the outer edge of the hat brim, near the right eyebrow. Soldiers wearing helmets or uncovered would bring their right hand up to their brow in a similar manner. Other militaries around the world may have slightly different variations of the salute, but the general concept remains the same - it is a gesture of respect and recognition.