Java is a language that people use to tell computers what to do. An arquebus is an old weapon that people used a long time ago to shoot things.
A Java arquebus is a type of computer program that helps people shoot things in a game. But instead of shooting real things, it's shooting things in a virtual world on the computer.
The Java arquebus helps make the shooting happen by using code, which is kind of like a set of instructions for the computer. The code tells the computer what to do when someone tries to shoot something in the game.
For example, if you try to shoot a monster in the game, the Java arquebus will use code to make the computer show a bullet being fired and maybe even show the monster getting hit.
So, the Java arquebus is a special program that helps make shooting in a game possible using the Java language.