You will get 15 random names for pirate crews and related forms of robbers. The names usually match best pirates, but a large range of names are appropriate for all kinds of (seafaring) robbers. Others are more playful, like One Piece, when other names are more intense. The names were divided into three groups, but the only real difference is how names are formed. Some divisions share sections of the same name, but there are also names belonging to just one category.
To generate another 15 random names you just have to press the button. With every click 15 new names are generated.