JRC, Tivo is basically a big meaty VCR that's fairly smart, and doesn't use any tapes. You say, "Dear Tivo, I would like to see everything with Bill Murray in it. Next, record The Daily Show whenever it's on. I'd like an episode or two of Spongebob Squarepants as well." Et cetera.

You sit down to watch TV and can watch whatever has been recorded, "Oh, hey! The procrastination episode of Spongebob!" -- just like you had spent time programming a VCR. You can mark a show to "save until I delete" if it was really good.

Of course you can watch live TV, and pause/rewind/fast forward, but I don't think I have used that feature more than a couple times.