Unless you’re running a major business out of your house, chances are you won’t need or be interested in the ability to do video conferencing with dozens of people at the same time. The same goes for an auto attendant and business software integrations. First decide which features are priorities for you (unlimited calling, voicemail-to-email, international calling plans, etc.) and then take a look at what each company offers. After all, there’s no sense in paying for features that you don’t need.
VoIP service simply enables your phone calls to be transmitted and received over your home Internet connection instead of your telephone landline. This is perhaps why some people refer to the service as being an Internet phone service or broadband phone service. This does mean though that you need a high speed Internet service to be able to use VoIP for your phone service.