An aide-de-camp (UK: /ˌeɪddəˈkɒ̃/ or US: /-ˈkæmp/;French expression meaning literally helper in the [military] camp) is a personal assistant or secretary to a person of high rank, usually a senior military, police or government officer, a member of a royal family, or a head of state.
This is not to be confused with an adjutant, who is the senior administrator of a military unit.
The first aide-de-camp is typically the foremost personal aide.
In some countries, the aide-de-camp is considered to be a title of honour (which confers the post-nominal letters ADC or A de C), and participates at ceremonial functions.
The badge of office for an aide-de-camp is usually the aiguillette, a braided cord in gold or other colours, worn on the shoulder of a uniform. Whether it is worn on the left or the right shoulder is dictated by protocol.