These ships are armed for defense. Escort vessels provide offensive capabilities. The first line of defense is information provided by the department of defense through satellite, long distance radar, sonic detection buoys, intelligence, etc. The ship's radar can detect threats from a few hundred miles away. The RAM missiles are deployed first from the box like turret. They can shoot down cruise missiles, planes, etc. The missiles spin in the air like a rifle bullet and this gives them stability. They cost 2.3 million dollars each and they did not fire them for test. They said they are reliable. A Harrier jet flew past and the missile launcher moved to track it. The rockets are self-guiding so they will seek the target on their own after it is identified and they are launched.
The 25mm machine guns are the next biggest armament. They are a close-in weapons system for defense against small ships and nearby targets. They are effective up to 2000 yards. They are remote controlled fro inside the ship or shot manually by crew members on deck. Some members of the ship crew were learning how to shoot these. They were having a lot of fun. It is the single barrel large machine gun in the pix.
The 20 mm phalanx machine gun is the last line of defense. It can track targets on its own. Humans are too slow to react and to do it effectively. It can shoot down missiles and planes. The fire rate is incredible since five barrels are being loaded and shot.