Unlimited recording means you can record audio/video with up to 8 participants in the Studio for any length of time. Riverside will not prevent you from recording more than the hours included in your subscription plan.
Each month, you can download the locally recorded separate high-quality tracks from your recording sessions, up to the number of monthly hours included in your subscription plan.
On every Riverside plan, you can always export and download an unlimited amount of clips and combined recording tracks from the Editor.