 I've got a simple Godot project here where health bar decreases over time from a previous screencast I've got some code set up where I reference a health label and a health bar throughout and There's a different way that you can reference these we can create a variable called health bar and Not assign it any value and then in the ready function when our scene our node is ready We can then say health bar is equal to the Dollar sign health bar so to that node in the scene and then we can refer to it throughout in a way that is a Little more resilient so we can have our variable name here and if the name of our Health bar node changes. We only have to update it in one place and you also you might just other see people do This type of thing too in the code. So I just want to explain it quick So now we've got the health bar and the health label We'll change these to be the variable name And let's see what the problem is Okay, we need to also declare bar health label up here so that we have an all variable to put that in We'll go ahead and run the game again, and we'll see that hopefully everything works. It does setting this variable here and Then also initializing it to a value on ready because these don't exist yet It's a little duplicative. You can simplify your code to say on ready. So at sign on ready there for for variable Health bar, and then you can say is equal to our health bar node and you can just delete this line of code So now it's quite a bit simpler and cleaner and we can do the same here, but let's see what happens if we Don't do on ready for health label We already get an error that says the default value for dollar sign to get the node before Ray is called do on ready annotation to Fix that so it already knows that we want to do that to make that better. So That's the equivalent doing this is the equivalent to the code We just had we declare the variable is no longer you said it and then now we can easily reference these nodes here And if we changed it, you know, if we change this to for some reason LB L Run it again. It's gonna fail Because it's not It's null. So then all we would do here is we would just rename it It'd be nice if Godot renamed that in the GD script that would make the code a little more resilient, but Generally fine that using on ready there your balls can really help with that So that's on ready variables explained nothing too fancy. You'd use a variable Normally without the annotation when you have the value that you can set ahead of time Like max health is declared here. So we can assign it to health without on ready But if in some reason if your variable relies upon like a node That's a child that the script is associated with or some other value Like maybe Yeah, another node you would use on ready there or you would just set it in the ready callback That's a little quickie. Hope it helps explain what that is. Thanks for watching