Yahoo! Messenger allows you to exchange instant messages and PC-to-PC voice calls with your online friends. If you subscribe to the Phone Out by Yahoo! Voice service ("Phone Out"), you can also use Yahoo! Messenger with Voice to make calls to normal landline or mobile phones.
You must be a registered Yahoo! user in order to use Yahoo! Messenger. Yahoo! Messenger establishes a connection to the Internet when it is active -- much like a browser does -- in order for communications to be received and transmitted.Information Collection and Use Practices