You mean how to stop a RAM Preview?
Yes, but during the render process.
I'm confused. Do you want to stop a preview or a render?
The preview.
You click the same thing that you start it with.
That doesn't work while you're actually rendering the video.
I figured it out anyways, it was the CAPS LOCK key.
You said you wanted to stop a preview, not a render. You can't do both at the same time.
I wanted to pause the preview of the render which shows while the video is the render process.