Some companies that want you to connect to the Internet through their services harangue you with advertising jargon about increased bandwidth. Technically speaking, bandwidth is a measure of the range of frequencies a given signal occupies. That's rather obtuse, however, when we talk about connecting to the Internet. If you're downloading text, that's a lot of information. However, if you're downloading graphics, sound files, animation, streaming video, and other data types that are extremely large, it's rather slow.
Modems provide the least amount of bandwidth of any Internet connection type.
On the other hand, they're inexpensive, they permit you dial in to Internet Service Providers that have inexpensive monthly fees, and they are reliable. Other options include ISDN lines, cable modems, and DSL connections. It depends on your Internet use and your level of patience. I was discussing this with a neighbor recently, someone who does a lot of research on the Internet. He told me he didn't care about bandwidth and wasn't going to spend money enlarging his bandwidth capabilities because he didn't download.