Was this really a question in an Algebra course??
If you are in Calculus it is not good that you do not know what a derivative is. Being able to compute the derivative of a function is good but you need to know when you need to compute the derivative and that requires you to know what a derivative is.
Suppose you have the function f(x) = x2. Please draw that function so you can follow along. The derivative of f(x) = x2 is denoted by f'(x) and f'(x) = 2x
Go to the point (1, 1) on f(x) and draw the tangent line at this point. The slope of this tangent line is f'(1) = 2(1) = 2.
Go to the point (3, 9) on f(x) and draw the tangent line at this point. The slope of this tangent line is f'(1) = 2(3) = 6.
Go to the point (-2, 4) on f(x) and draw the tangent line at this point. The slope of this tangent line is f'(1) = 2(-2) = -4.
Go to the point (-4, 16) on f(x) and draw the tangent line at this point. The slope of this tangent line is f'(-4) = 2(-4) = -8.
What do you find when you take the derivative of a function? The derivative f'(x) is a function that gives you the slope of the tangent line of f(x) at any point.