What does it mean to "render" a song?

“Render” usually identifies the very last processing that the program does to result a file that have been put together from the user on the program.

And so, it’s including, if you might have some sound recording editing software and also you are investing in different monitors and creating changes to obtain it to be able to sound perfect, and then you wish to export the work to help an CD file or even something, after you “export” your own work with a file, the enhancing program masters a “rendering” course of action where this puts all of the elements for you to assembled jointly and outputs them as a single archive.

http://en.wikipedia.org/wiki/Render.