If you're watching live TV, you can usually rewind the program that you're currently watching by up to 30 minutes. This is because most channels buffer the live stream by about this amount, in order to accommodate viewers who want to pause or rewind. So if you tune in late to a show or miss something important, you can usually go back and watch it. Of course, there are exceptions - some channels don't allow pausing or rewinding at all, and others only allow it for a limited time. And once a show has aired, it's often unavailable on demand. But if you're watching live TV, you can usually go back and watch what you missed.