VoIP is a modern day communication system based on internet protocols. Yes, you can use VoIP phone system for your small business which will cost lower than traditional phone systems.

Yes, you can. You need to plug your VoIP phone system adapter into any available broadband connection and you can use it anywhere in the world.
Generally, it will cost around $500-1000 per user.
A PBX (Private Branch Exchange) system is a private network used by a company or organization where employees or agents can communicate with each other as well as beyond the company through VoIP communications.
Yes, there are many providers offering free VoIP phone system. VoIPtechSolutions provide you best in the class free trial as well. You can contact us whenever you need to have a free trial.
VoIP phone uses internet protocols which can be encrypted as well. So it is more secure than traditional phone lines.