if c is the plane through the following points

(0,1,1) (0,1,0) and (-2,-1,-1)

how can I find an equation and parametric description of the plane?

I know the equation of the plane can be written as

a(x-x0) + b(y-y0) +c(z-z0) for a point (x0,y0,z0) and a normal vector (a,b,c)

how can I find the normal vector from the points?

I am also not sure about the difference the equation and parametric representation

thanks.