Rear admiral is the lowest of the admiralty ranks and is the next step above the rank of captain. Someone at this level handles more direct supervision of lower ranking officers than higher-ranking admirals do. During military operations, all admirals command more than one ship within a fleet.
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Rear Admiral is a naval commissioned officer rank [...] below that of a Vice Admiral. It originated from the days of naval sailing squadrons and can trace its origins to the Royal Navy. Each naval squadron would be assigned an admiral as its head, who would command from the centre vessel and direct the activities of the squadron.
https://english.stackexchange.com/questions/10604/what-is-the-difference-between-admiral-and-rear-admiral
Rear admiral (United States) Rear admiral in the United States refers to two different ranks of commissioned officers — one-star flag officers and two-star flag officers. By contrast, in most nations, the term rear admiral refers to an officer of two-star rank.
https://en.wikipedia.org/wiki/Rear_admiral_(United_States)
Navy officers wear their rank devices in different places on their uniforms, depending upon the uniform. The three basic uniforms and the type of rank devices are: khakis (a working uniform) -- pins on the collar; whites -- stripes on shoulder boards; and, blues -- stripes sewn on the lower sleeve.
http://www.navy.mil/navydata/ranks/officers/o-rank.html
Vice Admiral. The vice admiral is above both levels of rear admirals in the military hierarchy. He has three stars on his uniform and his rank is equivalent to a lieutenant general in the army, with a pay grade of O-9. A vice admiral is almost at the top of the ranks with only one rank above him in times of peace.
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From Wikipedia: Rear Admiral is a naval commissioned officer rank [...] below that of a Vice Admiral. It is generally regarded as the lowest of the Admiral ranks[.] It originated from the days of naval sailing squadrons and can trace its origins to the Royal Navy.
https://english.stackexchange.com/questions/10604/what-is-the-difference-between-admiral-and-rear-admiral
REAR ADMIRAL. Rear admiral (RAdm) is a flag officer rank of the British Royal Navy. It is immediately superior to commodore and is subordinate to vice admiral. It is a two-star rank and has a NATO ranking code of OF-7. The rank originated in the days of naval sailing squadrons and each naval squadron would be assigned an admiral as its head.
http://www.militaryfigures.co.uk/military-ranks/royal-navy-ranks/rear-admiral
They serve indefinitely at the pleasure of the President of the United States. They hold a commission charging them with the duties and responsibilities of their specific rank. Officer ranks consist of commissioned officers and warrant officers (specialists and experts in certain military technologies or capabilities). Promotion of officers are confirmed by the Senate.
http://www.military.com/navy/officer-ranks.html
Rear admiral (lower half) is equivalent to the rank of brigadier general in the other uniformed services, and equivalent to the rank of commodore in most other navies. In the United States uniformed services, rear admiral (lower half) replaced the rank of commodore in 1985.
https://en.wikipedia.org/wiki/Rear_admiral_(United_States)
Additionally, line officers wear a star above the stripes of the shoulder boards or sleeves but staff and warrant officers wear specialty insignia. * The rank of Fleet Admiral has been reserved for war time use only. The last Fleet Admirals were in World War II.
http://www.navy.mil/navydata/ranks/officers/o-rank.html
what rank is rear admiral
Rear admiral is the lowest of the admiralty ranks and is the next step above the rank of captain.