what is answer to y=x-3

Is this a slope or a coordinate graph plotting...for every value for x there is a y-value, associated with the equation y = x - 3 Imagine or draw a table... if x = 0 then: y = 0 - 3 and y = -3. Do you understand? What has to be identified is is this a slope coordinate problem or a simple solve for the unknown. Thanks J