what do you mean what kind of disc am i trying to create? i want to copy movies to disks
Well a movie sat on a hard disk is just a file so you can burn it to any disk that is big enough to fit the file on. Just like any other type of file.
You can do this in finder, with Toast, and many other bits of burning software.
Alternatively you could be wanting to create a VCD, SVCD, DVD, Blu-ray disc or mixed mode data and video CD..... the list goes on.
I suspect what you want to do is convert a movie (xVid, divX, mkx etc) to a format that can be written to a standard single layer DVD so that you can play it back on an off-the-shelf DVD player. But I don't know for sure.
The format of the original file and the type and format of disc you want to create will determine the software you'll need to use.
All of that said the link I posted previously lists software to can convert most video formats to most other video formats. e.g they can take man_walks_dog.avi and convert it into the the correct file structure and video types for burning to a DVD-R with the burning software of your choice
HTH
mrplow