Region fades are possible at the beginning and end of all audio regions. In object mode, a grip appears at the top left and top right of an audio region when the cursor hovers over it. Placing the cursor over the top of the grip displays the region fade cursor tip. Click and drag the grip left or right in the timeline to adjust the length of the fade.
To activate/deactivate or change the shape of the fade, hover the cursor over the regionfade grip till the cursor tip indicates region fade editing and context-click to bring up a context menu. In the context menu there is a list of options for the regionfade. Activate/Deactivate enables and disables the regionfade. The different types of fades are, Linear, Slow, Fast, Symmetric, and Constant Power.
Crossfades refer to the behavior of a region fade when regions overlap other regions. Crossfades are regionfades. When one region overlaps another and there is a regionfade on the top region the fade-out will be mirrored as a fade-in on the underlying region. The grip for the top region will allow changing the length and type of the crossfade.