Modern warships need active defenses and physical protection

What is the modern equivalent of naval armor: close-in weapons, electronic systems, or passive materials?

Both active and passive protection are necessary: layered defenses keep threats away, while armor and subdivision reduce damage when something gets through.

Active defenses should engage threats at the greatest possible distance and continue through close-in weapon and electronic layers. Their purpose is to keep missiles, aircraft, and other weapons away from the hull whenever possible. Because no interception system is perfect, key spaces still need physical protection and redundant arrangements. Subdivision then limits flooding or fire after a hit, making passive protection the necessary final layer rather than an alternative to active defense.