Bézier curves come in two flavors, quadratic and cubic. The naming of these guys has always tripped me up, because quadratic curves have three control points and cubic curves have four.
Wait, that sounds backwards. Quad = 3, cube = 4?
Turns out that the word "quadratus" is latin for "square". Which in a roundabout way makes sense because there's four sides to a square. And quadratic bézier curves get their name from being a 2nd order curve (cubic béziers get their name from being a 3rd order curve).
Why oh why, didn't they name it the Square Equation, or something more sensible? Then I wouldn't have felt so dumb about confusing quadratic and cubic and cuves for all these years.
Anyway, here's a little graphic I just made in Acorn 3.5 using the new Sunburst filter: