The domain is the set of all first elements. These "first elements" are referred to as the independent variable, or X.
example: (0,0), (8,9), (5,5), (4,2)
The domain of the set is {0, 4, 5, 8}

Range

The range is the set of all second elements. These "second elements" are referred to as the dependent variable, or Y.
example: (0,0), (8,9), (5,5), (4,2)
The range of the set is {0, 2, 5, 9}

Visual Display

The data in the set can be displayed visually. The two types of visual presentations are mapping diagrams (left) and graphs (right).
example: (0,0), (8,9), (5,5), (4,2)