Dynamic property access perhaps? The premise is that you can always access an object's properties using indexing syntax as well as the normal dot syntax. So `o

Dynamic property access perhaps? The premise is that you can always access an object's properties using indexing syntax as well as the normal dot syntax. So `object.foo` is the equivalent of `object["foo"]` or `object["f" + "o" + "o"]` (because the value inside the square brackets can be any expression). And if `object.foo` is a method, you can do `object.foo()` or `object ["foo"]()` or whatever else as well. Normally, the key expression will always be coerced to a string, so if you did `object[2]`, this would be the equivalent of object["2"]. But there is an exception for symbols, which are a kind of unique object that is always compared by reference. Symbols can be used as keys just as they are, so if you do something like const obj = {} obj.foo = "bar" obj[Symbol("foo")] = "bar" console.log(obj) You should see in the console that this object has a special key that is a symbol, as well as the normal "foo" attribute. The last piece of the puzzle is that there are certain "well known symbols" that are mostly used for extending an object's behaviour, a bit like __dunder__ methods in Python. Symbol.dispose is one of these - it's a symbol that is globally accessible and always means the same thing, and can be used to define some new functionality without breaking backwards compatibility. I hope that helps, feel free to ask more questions.