Unmetered bandwidth means that the server has part or all of a dedicated connection, and we don't make any extra charges (i.e. you cannot "overuse" the connection). The sharing ratio is called contention.
Unmetered does not mean infinite however - for example an unmetered 1Mbps connection gives a maximum transfer of roughly 400Gbytes/month.
If you would rather have a burstable connection and pay per GByte then we also offer metered connections.