Skype

  Skype (pronounced /skaɪp/) is a software application(应用软件） that allows users to make voice calls over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones（固定电话） 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（即时通讯）, file transfer（文件传输）, and video conferencing（视频会议）. The network is operated by a company called Skype Limited, which has its headquarters in Luxembourg （卢森堡）and is partly owned by eBay。

  Registered users of Skype are identified by a unique Skype Name, and may be listed in the Skype directory [diˈrektəri]（目录）. Skype allows these registered users(注册用户） to communicate through both instant messaging and voice chat（语音聊天）.Voice chat allows calls between pairs of users and conference calling, and uses a proprietary [prəˈpraɪɪˌteri:]（专有的）audio codec（音频编码解码器）. Skype's text chat（文字聊天） client allows group chats, emoticons(表情，图释）, storing chat history, offline messaging （离线发送信息）(since version 5) and editing of previous messages. The usual features familiar to instant messaging users—user profiles（用户配置文件）, online status indicators[ˈɪndɪˌkeɪtəz]（指示器）, and so on—are also included.