Some regular lines with a monthly fixed payment have separate charges for other features. Additional payment is needed to have unlimited long distance. Others don’t come with free voicemail. Caller id, call waiting and call forwarding have different charges as well. This depends on the plan that is subscribed.
VoIP have a fixed monthly charge which includes the features. And because it will be using your internet, it does not have the line rental. Local and long distance are both unlimited. Some providers can give you unlimited call to Canada. There are a variety of plans to choose from.
Whichvoip.com can give you more information on the service and has a breakdown of the comparison.
Source: whichvoip.com