It is a method of communication based on text messaging between two fax machines, the first one calling to other one to send a fax, the recipient receives a text on A4 paper and after that communication process ends.
What is Google Talk, you ask? In short, this feature of Google is the year 2012’s answer to instant messaging services. It takes the idea associated of online text messaging, and has updated them to include a variety of other aspects, all with one goal in mind: to make the user’s life easier. Imagine a Talk outlet that allows you to chat and share whatever is on your mind, and also fuses together concepts made popular by VOIP and SIP technologies, and you have a good starting overview on the innovative technology Google Talk provides.