O-5 and O-6 are senior officers:
commander and captain.
O-7 through O-10 are flag officers:
rear admiral (lower half) (one star),
rear admiral (two-star),
vice admiral (three-star), and
admiral (four star).
https://en.wikipedia.org/wiki/Rear_admiral_(United_States)
https://en.wikipedia.org/wiki/Collin_P._Green
https://www.rt.com/usa/502302-trump-gender-navy-seals/
https://twitter.com/realDonaldTrump/status/1311787312980930561
https://twitter.com/ColumbiaBugle/status/1311783194967117826
https://twitter.com/Breaking911/status/1311781162373836815
https://twitter.com/Breaking911/status/1311788312852602881
Collin Patrick Green[1] (born 1962) is a rear admiral in the United States Navy, who serves as the commander of the Naval Special Warfare Command.
He graduated and was commissioned from the United States Naval Academy in 1986. Green also holds degrees from the Catholic University of America and United States Naval War College.[2]
He is a naval special warfare officer and previously served as commander of United States Special Operations Command South from 2016 to June 2018.[3]
Green will step down from his current post in September 2020, a year early. Some believe this is due to his interactions with President Trump over the decision by the president to reinstate the rank of SEAL Eddie Gallagher.[4]
Trump vows to revoke ‘ridiculous’ gender-sensitive Navy SEAL changes IMMEDIATELY
1 Oct, 2020 23:56 / Updated 20 hours ago
5:57 PM · Oct 1, 2020·Twitter for iPhone
I will be overturning this ridiculous order immediately!