Hulu: a website that features streaming of recent episodes of television shows, entire catalogs of older shows, movies, etc. At this point free, though there are constantly rumors that there will be some sort of pay service in the future. Streaming does have commercials. on wikipedia
Netflix: first, is awesome. It’s a subscription service to rent DVDs through the mail, and in the past few years has also added instant viewing (streaming video) to the website for selected titles. A user pays a monthly subscription fee, and receives DVDs in the mail, there is no due date or late fees, you just don’t get another DVD until you return one that you have. on wikipedia
DVR: means digital video recorder. Kind of like a VCR, but better (and often with no commercials!) on wikipedia
NPR: National Public Radio, which is non-profit that syndicates radio shows in the US, which many of us listen to on our local affiliate stations. About NPR. My experience is that you can listen to it outside the US (at least you used to be able to), the general site is here. This isn’t to be confused with PBS, Public Broadcasting Service, which is non-profit television, and is the channel on which many of us watched awesome kids shows and Cosmos.