Domain and range is a bit confusing for me. I'm currently taking pre-calc. This is my first week of it and I have gotten most of it up until the test. I can't seem to get past the first question. :( Could you please help me out a bit?

Imagine a mapping from the set of all integers onto the set of all nonnegative integers in which the set of ordered pairs is:

{(0,0, (1,1), (-1,2), (2,3), (-2,4), (3,5), (-3, 6), (4,7), (-4,8),...}

Is this relation a function? If so, why? If not, why not? Is its inverse a function? If so, why? If not, why not?

I don't quite understand how I would approach this. Thank you for your help.