That's about it. There's other ways to record also, by title, season-pass, time, channel, ect. Are you looking at SD or HD? In either case, you can always hit record for what you're watching. Recording, temporarily, essentially begins everytime you change a tuner. All the models, SD and the HD box all have two tuners. Really, you're just instructing that the current recording/s are saved.
my main question is if it works the exact same for satelite channels and off air stuff, this is for my dad, and i want it as easy as possible, without switching to a different input if possible
If it's the HD model, yes. If it's the SD model, yes, if you buy the local channels, it can't record off the air. The SD model has 2 satelite tuners. The HD model has 2 satelite tuners and 2 OTA tuners.
Jeremy Rachael is always right! Just a little to add. I had originally a stand alone Directv box and a seperate TIVO. I found that combination akward and a real problem for my wife to use. I was trying to ween her off me as her own 'personal recorder'. Quality was disappointing too. Sold those and got a 2 tuner Directb box and it works great! Cheers