In the equation $y = ax^2 + bx + c$ of a parabola, what do "$a$", "$b$", "$c$" represent? I have trouble grasping some basic things about parabolas. (This should be easily found on Google, but for some reason I couldn't find an answer that helped me).
I know one simple standard equation for a parabola:

$$y = ax^2 + bx + c$$
My problem is: I'm not sure what the following letters represent: $a$, $b$, and $c$.

Please try to explain to me what each of these letters represent in the equation, in a simple manner so I will understand, since I have very basic knowledge in math.
Thank you
It would be worth your while to learn another standard form of the equation of a parabola, and you can complete the square, given $y = ax^2 + bx + c$, to obtain this form:

$$4p(y - k) = (x-h)^2$$

The vertex of the parabola is given by $(h, k)$.
$$h = \frac{-b}{2a};\quad  k = \frac{4ac - b^2}{4a}$$

$$4p = \frac 1a$$
So, we have f(x) = ax^2 + bx + c, where a is distinct from  0.

'A' is related with growth. If 'a' is negative, function decrease, if 'a' is positive, function increase. 'C' is of course y-argument of point (0, f(x)) (let's imagine this as a place where function cross OY axis).