Question about built in bukkit permissions?

Soo when making a plugin you can make permissions using the build in method in bukkit but what is that called exactly and if I use it will it work with all permissions plugins or only the ones who support it?
Example:
if (player.hasPermission("WTFBBQ.HAX")){
}

 

it will work whit only the plugins supporting it, I know sure the following plugins support it (there may by more) pex, permissions bukkit, bpermissions

 

So is it just Bukkits built in Permissions Handler? and then the other plugins have linked into it?

 

see its like an compactability layer that allows manny permissions plugins comunucate whit manny other plugins, whitout hooking to them all
like java
you write an java app, and it works on al platforms, whitout to need to write for each platform some other code