At various places in the app there is the option to define the curve that defines how a value should evolve from point A to B.
For example in the breakpoint envelopes imagine you have a point at 30% and the next point is at 70%. Then question is: How should the value evolve over time?
The most straightforward way is using a straight line, this is called linear. But you could want to let it evolve in other ways eg exponential etc.
That's what the curve definition is all about.
In the above picture you see a curve edit display. You can drag in the little curve display to change the curve's primary parameter.
See below for more details on the curve parameters. If you want to edit the curve in full detail then doubleclick the curve display or click the options button at the right. This will popup the curve editor:
Click the "Type" field to select a curve type from the list. Each type can have up to 2 parameters that further shape the curve. Some examples:
 Example 1: The "Exponential" curve type has a single parameter named "Intensity".
 Example 2: The "Sine" curve type has a primary parameter named "Num Quarters" and a second parameter named "Start Quarter".
 Example 3: The "Sine Q1" curve type has no extra parameters as it strictly is the first quarter of a sine wave.
Select the curve type and adjust its parameters until you have the curve you want.
Note that thanks to the rich choice of curves you can even create LFO shapes with it.
The Exponential type's Intensity parameter is optimized for practical use, it varies between 32 (instant end value) to +32 (hold start value).
But sometimes you might need to set an exact exponent value like 2 = squared. To do so rightclick the Intensity field to set an effective exponent value.
