What is this bar?

I’ve been using the Unreal Engine: how to make an inventory system, but i’m having to start from scratch, and I can’t figure out what #2 is, I’m pretty sure #1 is a Float / Float but what is #2?

Hard to see the screenshot, but #1 looks like an int/int node, and “a” is an Int to Float node, it casts/converts an int to a float. If you drag an int into an input that takes a float, it will automatically create the node for you. Or you can drag off from it and type “To Float”.

thank you, that was it.!