Answer
The given relation defined a function.
domain: $[-2, 2]$
range: $[0, 4]$
Work Step by Step
Note that all vertical lines will pass through the graph in at most one point. This means that the graph pass the vertical line test.
Thus, the given graph represents a function.
The graph covers the x values from $-2$ to $2$.
This means the domain is $[-2, 2]$.
The graph covers the y values from $0$ to $4$
This means the range is $[0, 4]$.