Admiral is the second-highest rank in the Marine Organization. They are one rank below Fleet Admiral and one above Vice Admiral. The three Admirals are considered some of the strongest characters within the One Piece world.
The admirals have been crowned the title of the World Government's "Greatest Military Power" and are considered the strongest individuals within the World Government. Also, there are only three people who are allowed to become Admirals at a time. Just the presence of one Admiral is enough to cause wide-spread panic on an island and cause an entire population to flee. Their presence is enough to deter even the strongest pirates from causing any problems.
Every single Admiral has shown to be capable of utilizing Haki, and Advanced forms of Haki. The different capabilities between an Admiral and Vice-Admiral are very drastic. Admirals are on another level when compared to the Vice-Admirals. So far, every Admiral has been shown to have some sort of Devil Fruit.
Every Admiral is proficient in at least one fighting style, but they are usually capable of using two kinds.
Each Admiral can command over thousands of soldiers that are ranked beneath them. Only the Fleet Admiral and Admiral are allowed to use the Buster Call. They are also the only ones that can grant others the usage of the Buster Call. Only the Five-elders, Fleet Admiral, and Commander-in-chief are superior in terms of rank.
Each Admiral is a direct subordinate of the World Nobles. If one is opposed or injured then an Admiral can be summoned to take the opposing party down. Failing in this task is unacceptable.
With evidence, the Admirals have enough Authority to revoke the title Shichibukai of their title as well as pardon those below the Schichibukai. Although, other ranks can also do this with enough evidence.