Built-in VariablesThe new version of Google Tag Manager introduced Built-in variables. These are helpful, most commonly used variables, whose existence is based on binary logic: active / inactive. If the Built-in variable is activated, it can be used as any other variable, and if it's not activated, it can't.Built-in variables are thus no more than a shorthand for exploiting some of the most frequently used variable types in Google Tag Manager. I find it a bit odd that they're not all activated by default, since there's absolutely no harm in them being available for use.You will find the Built-in variables displayed prominently in the top of the variables screen of your Google Tag Manager Container: