An officer was a member of a group typically in the areas of the military, police, or some other form of authority. In a military service, an officer's typical role was to command and direct, maintain discipline, and make plans and provisions for operation. Certain organizations had special criteria in order for one to achieve the status of officer.
Commission
In a military service, a commission was an order from the service's supreme authority, such as its commander-in-chief, authorizing an individual to legally hold a military rank, with all the privileges and responsibilities of said rank. A commission usually appointed an individual to hold an officer's rank. (citation needed • edit)
In times of conflict, a temporary commission could appoint an officer to command rank to replace an incapacitated or killed commanding officer. (citation needed • edit) Commander William T. Riker, for example, was granted a field commission promoting him to captain and given command of the USS Enterprise-D when the ship's commanding officer, Captain Jean-Luc Picard, was abducted and assimilated by the Borg during their first attempt to assimilate Earth. (TNG: "The Best of Both Worlds", "The Best of Both Worlds, Part II")
In situations where contact with Starfleet was not possible for very extended periods, a commanding officer had the authority to grant commissions to officers under his or her command, or revoke their existing commissions; that is, he/she had the authority to promote or demote his/her officers. (citation needed • edit) Examples of this are when Captain Kathryn Janeway, commanding officer of the USS Voyager, promoted her chief tactical officer and security chief, Lieutenant Tuvok, to the higher rank of lieutenant commander, or when she demoted her flight controller, Lieutenant junior grade Tom Paris, to ensign. (VOY: "Revulsion", "Thirty Days") After a year of exemplary service, she reinstated him to his former rank. (VOY: "Unimatrix Zero")
Starfleet
Jean-Luc Picard of the USS Enterprise-D with the rank of captain
In the Federation Starfleet, an officer or commissioned officer was an individual who had attended and graduated from the four-year cadet program of Starfleet Academy. (citation needed • edit) Upon graduation from the Academy, the cadet was granted a commission appointing him or her to the rank of Ensign, or in exceptional circumstances Lieutenant junior grade. (citation needed • edit) Trades such as Doctor or Counselor graduated as a Lieutenant junior grade as standard due to the extra time spent studying before graduating. (citation needed • edit) With the commission came a Bachelor's degree in his or her major field of academic study, be it the pure sciences, medicine, military science, etc. (citation needed • edit)
Commissioned officers, as with enlisted officers, were organized by a rank structure. (citation needed • edit)
Commissioned officer rank structure
Starfleet ranks from lowest to highest:
- Ensign
- Lieutenant junior grade
- Lieutenant
- Lieutenant commander
- Commander
- Captain
- Fleet Captain
- Commodore (aka rear admiral lower half)
- Rear admiral (aka rear admiral upper half)
- Vice admiral
- Admiral
- Fleet admiral
Other officer terms
- Certain officer positions could be filled by non-commissioned officers and civilians if the need arose.
By rank
- Field officer
- Flag officer
- Line officer
- Ranking officer
- Commissioned officer
- Provisional officer
- Non-commissioned officer
By title
By command structure
By department
An engineering officer in Starfleet (2364)
- Helm officer
- Navigator
- Operations officer
- Engineer
- Tactical officer
- Security officer
- Weapons officer
- Armory officer
- Intelligence officer
- Communications officer
- Medical officer
- Science officer
- Counselor
- Mess officer