DVD up-scalers have been everywhere lately. We have done tons of posts about them the last few months and even an in-depth review of one of the newest ones on the market. But they can be confusing. We have located the best explanation of what they do and why they are good. While we are not as excited about them as this author is - he presents it like it is a gift from God - they do work good sometimes. Before you get out your pocket book though, many high-end HDTVs have great scalers built in so you might not see any improvement over your current progressive scan DVD player.