We explain the difference between digital and high-def, and offer advice on when to buy

They’re here! Well, okay, sort of. Digital and high-definition television have hit the market, and even though surveys show that more than two thirds of us have heard of them, only techies know precisely what they are. But by May 2002, Uncle Sam says all of us must have access to DTV. Here’s a guide to help cut through the clutter.

WHAT IT IS (ACTUALLY, WHAT THEY ARE) Digital TV is — of course — a digitized 1s-and-0s version of regular analog TV; you can watch it over your existing set, and the clarity is only slightly impressive. What makes you go ”Whomp, there it is,” is HDTV, or high-definition TV. Invented by the Japanese in the mid-1980s and available in 1995, it offers Dolby digital surround sound and the same wide, rectangular screen you get in theaters when you’re manipulated to weep over Titanic. How good is it? Imagine a nearsighted kid donning glasses for the first time. Because an HDTV monitor has double the resolution lines of your current box, you’ll feel you can reach out and pluck that can of beer from Drew Carey’s hand. Finally, on the far-out horizon is the amazing 3-D HDTV, in which a show like Baywatch will become too topographically frightening to think about.

WHAT YOU NEED TO SEE IT Right now, digital TV via satellite — in which companies like DirecTV place an 18-inch, $200 dish setup in your backyard — is your quickest, cheapest option: For about $30 a month, you get a better picture and programming that you already get on cable. Unless you’re Gates or Trump, though, an HDTV set will max out your credit with its out-of-reach $8,000-plus price tag. You can cheat with a $400-plus box that ”converts” digital signals so that your analog TV transforms into a digitized, rectangular fake high-def, but since it doesn’t increase the number of scan lines, this takes the Milli Vanilli bait-and-switch award.

WHAT YOU CAN WATCH Ain’t much currently. ABC will probably be broadcasting selected Wonderful World of Disneys in HDTV, a wise move, since the format is best with awesome panoramas and exotic faraway locations. NBC, on the other hand, gives us The Tonight Show in high-def, and who wants to see Leno’s butte-size jaw in near-3-D limpidity? CBS premieres HD football in November: The rectangular screen is perfect because you can eyeball the whole field.

WHY IT’S SO DAMN CONFUSING Remember the cliche ”Too many cooks spoil the broth”? Well, the government and broadcasters royally parboiled digital TV. When the FCC allotted new channel space to the networks in 1997, TV and tech execs couldn’t agree on whether they wanted to go digital or high-def — especially since the new band can support six channels of DTV or one of HDTV. The result? Eighteen different formats at last count, with brain-crushing names like ”zig-zag scan for coefficient coding.”

WHEN YOU SHOULD INVEST By the time Al Gore or George W. Bush takes the oath in the year 2001, HDTV sets should drop below five grand. At the end of term, they should be as cheap as current sets. By then, say the gurus, most TV programming will be either digital or high-def. Note: No one’s saying better.