Skype is a software application that allows users to make voice and video calls and chats over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system. Skype has also become popular for its additional features which include instant messaging, file transfer, and video conferencing. Skype has 663 million registered users as of 2010. Unlike other VoIP services, Skype is a peer-to-peer system rather than a client–server system, and makes use of background processing on computers running Skype software; the original name proposed – Sky peer-to-peer – reflects this.
About (from Skype Technologies at www.skype.com)
“With Skype, you can share a story, celebrate a birthday, learn a language, hold a meeting, work with colleagues – just about anything you need to do together every day. You can use Skype on whatever works best for you - on your phone or computer or a”