Broadband includes, Cable, all flavors of DSL, ISDN, T1 and up, isdn, fixed wireless and satellite.

between cable and DSL it depends alot on your provider, cable has more total banwidth, but you will be on a shared circuit with all your neighbors (if everyone is online at once, it slows way down.
DSL is a dedicated line between your house and the phone companies switch, you pay for the rate package you choose. some where between 350KBPS and 8MBps download 128k/1.5Mbps up in most cases