a stock is a wallpaper or a piece that is used similar to a render, but without being rendered. a render is a cut out from a stock/wallpaper/etc.
Renders may also be reffered to as crops, as a render literally means to create an image from computer software but it became casually used as the term for cropping a wallpaper of normally a gaming character! If people refer to stock they may be reffering to the original material used in their piece of art, ie dA has its section of stock photography which may be used for pieces of your own art.
If you want to be technically correct, renders are 3D models, nothing more nothing less. 'Stock" however, is a broad term that covers any and all images that are created/bought/sold/distributed/googled for design purposes. Stocks can be photos, CG images, vectors, or any other kind of images. People have a misconception that any cut-out image is called a "render", but that's incorrect terminology. The correct name would be "stock". Of course, if a gaming image was generated through 3D means, by all means call it a render. Anything else, however, would be a stock. This is all unimportant in the world of Gamerenders, so for your purposes, go ahead and call them whatever you want.
that would suck so bad to be called gamestocks.com It just doesnt roll *goes and buys the domain name*
