Bandwidth is the amount of data that can be transmitted during a fixed amount of time (stated in bits/second).

For example, a 56 Kbps network connection is capable of receiving 56,000 bits of data per second.

In website hosting, bandwidth is the amount information that can be downloaded from a server over a certain period of time.

For example, a web host might offer a website package that is allowed to have 2GB/month bandwidth. If visitors download more than 2BG of data in one month, they will have exceeded the bandwidth and there might be an additional charge.