The Chief of the Defence Staff (CDS) is the principal service advisor to
HM Government and he commands and coordinates the
activities of the three Services through the three single service
commanders. These single service commanders exercise command of their
single services through their respective headquarters.
DG - Director General
DCDS - Deputy Chief of the Defence Staff
The three single services, Royal Navy, Army
and Royal Air Force are the fundamental elements of Defence. The single
Service Chiefs of Staff (The First Sea Lord/Chief of the Naval Staff,
the Chief of the General Staff and the Chief of the Air Staff) are the
professional heads of their respective services.
However, the complex inter-service nature
of the majority of modern military operations, where military, air and
naval support must be coordinated, has led to the establishment of a
Permanent Tri-Service Joint Headquarters (PJHQ).