The fighters I am talking about are fighters in space, in real life, fighters are a useful asset in warfare because they can fight on a 3d plain where as ships can only fight in a 2d plain, in space, battleships can fight on a 3d plain just like fighters.
But since you bring it up, most naval ships are capable of shooting down a fighter squadron, not with the big anti ship guns but with the miniguns that use computers to track targets with extreme accuracy, just like fighters in a space battle would be able to shoot down a fighter squad with the same principle.
Fighters in real life can destroy a ship mind you, but in a space battle, a battleship would be fitted with lots of anti fighter armaments, such as flak, miniguns and maybe even heated lasers (heated lasers are in development for ships to shoot down cruise missiles)