What term is used to reply to an order or command meaning "I understand and will comply"?

The term that means "I understand and will comply" in a naval context is "Aye-aye." This phrase is traditionally used by service members when acknowledging orders or commands and signifies the listener's intent to execute the instruction as given. It reflects a commitment to following the chain of command and ensures that the individual understood the order clearly.

While "Roger" is commonly used in radio communication to imply that a message has been received and understood, it does not necessarily convey a commitment to comply, making it less specific than "Aye-aye." "Confirmed" and "Understood" are also valid acknowledgment phrases but are not standard in military communication when it comes to explicit compliance with an order. "Aye-aye" is uniquely suited for this purpose, demonstrating both understanding and a commitment to action in a military setting.