Identify the feature used in the second function.

The feature used in the second function is Expression Body Syntax. This allows for a more concise function declaration when the function consists of a single expression, by using an equals sign (=) instead of curly braces and an explicit return keyword.

• Expression Body Syntax: This is the correct technical term for defining a function's body as a single expression using the = operator.

The final answer is $\text{Expression Body Syntax}$.