Answer
$\text{domain: all real numbers}
\\\text{range: }
\{y|y\ge0\}
\\\text{a function}
$
Work Step by Step
Using the Vertical Line Test, a vertical line drawn anywhere will hit the given graph at only 1 point. Hence, the given graph is a function.
The $x-$values of the given graph can be any number, while the $y-$ values are always non-negative. Hence, the graph has the following characteristics:
\begin{array}{l}
\text{domain: all real numbers}
\\\text{range: }
\{y|y\ge0\}
\\\text{a function}
.\end{array}