How does VoIP (voice over Internet protocol) work? What makes it different from traditional phone service?

Three brief scenarios of how VoIP works..   1. when we place a phone call our voice signals are converted to digital packets   2. those packets travel via the Internet until they reach the final destination    3. at last the packets convert back to voice signalsPSTN (Traditional Phone Service) Disadvantages   1-  It requires a dedicated line for making and completing a call.    2- Scalability is limited.    3- You cannot use bandwidth optimally with this technology.    4- You need to pay maintenance fees every month.    5- Call charges are higher than VOIP.VOIP Advantages    1- VOIP is the newest technology for telephony. It transmits data by a packet switching method. This increases the effectivity of data transmission.    2- You can transmit data, video and voice at the same time.    3- It is scalable to a large extent.    4- Bandwidth is well utilized since the data is transmitted in a compressed form.    5- Not too much of hardware is needed since the internet is at the core of this form of communication.    6- There is a huge reduction in call costs by properly using bandwidth. This means that making calls via VOIP is cheap and easy.    7- You get free value added services.

the VOIP protocols is a suite of TCP/IP  package, it is work by converting the analog sound to packets of ip data using efferent types of protocols like SIP OR H.XXX  protocols , it is more cheaper & realble technology that traditional analog telephony systems