Encaustic is made of wax and natural resin, and it needs support - ideally wood panels. A cradled panel is one with braces on the sides and, if larger, across the back to keep it perfectly flat and strong.
This is what a bare cradled panel looks like:
I continue the encaustic down over the edges of my work so it can be hung without framing and look finished and clean.
Here's a ridiculously speedy video of the process: