DSL stands for digital subscriber line. The technology uses regular copper telephone lines to connect homes and small businesses to the Internet at high speeds. Those speeds typically range from 512 kbps to 1.544 mbps (nearly 30 times faster than a 56-kbps modem) for downstream transfers, which are downloads or file transfers to your PC. Upstream DSL speeds--file uploads and transfers from your PC to somewhere else--are usually much slower, around 128 kbps, depending on what type of DSL service you have.

Home users often end up with ADSL after talking to a DSL provider. That's because ADSL provides fast download rates, up to 1.544 mbps, and slower upload rates, from 128 kbps to 512 kbps. Home users are often more interested in downloading than in uploading or transferring files, so upload speeds aren't as crucial. SDSL, on the other hand, is a popular business option because, in most cases, it boasts the same upload and download speeds. However, quality of service and actual speeds vary, so quiz your provider before you buy.

If you're getting DSL for your home, it's a good bet you'll either be getting ADSL or DSL Lite, a lower-transmission-rate version of ADSL. In fact, as more home users jack into DSL, G.lite (also known as Universal ADSL) may become the most widely installed form of DSL. One reason is that G.lite doesn't require a splitter to separate voice and data traffic, so it's easier to install. This saves you time and money. What's more, G.lite provides potential downstream data rates of up to 1.5 mbps. Realistically, download rates are about 384 kbps, with upstream rates of up to 128 kbps--speeds that are still loads faster than a modem or ISDN.

DSL services are still in their relative infancy. Moreover, you still need to secure Internet access through an Internet service provider. Cable companies, on the other hand, provide Internet access along with the high speeds.  Anyone considering a DSL line has to be willing to put up with installation hassles. The telephone company will need to check your access and proximity to a local phone interchange; those who are too far away may be denied service. 

Both DSL and cable users run a new risk: hackers. Unlike a dial-up connection, where your computer gets a new IP (Internet protocol) address each time you hook up, your fast Internet service will likely come with a static, or permanent IP address. That means whenever your computer is turned on, it will be on the Net and others might be able to "see" you and monkey around with your computer from afar.