PODCAST

A podcast is a term compounded from the words iPod and broadcast, and it refers to content itself or the method by which it is syndicated（聯合）. It is a collection of digital media files for playback（錄放裝置）on portable media players（PMP） and pc. And the podcasting scripts, first developed for PMP, allow podcasts to be automatically transferred to a mobile device after they are downloaded. Some specific specialties of a podcast are, with RSS or Atom, an aggregator for reading feed（傳送）formats, its capabilities of being syndicated, subscribed to, and downloaded automatically when new content is added.

The feeds are distributed to the podcasting client which is the software for making full use of podcasts’ syndication functions. By liking to the audio file in an RSS feed or web page, users can download directly. Podcasting listeners can listen on the computer using media player software, through MP3 player, a specialized hardwre device, or with VoIP technology（Voice over Internet Protocol, a protocol optimized for the transmission of voice through the Internet or other networks）by calling to a virtual phone number.

Initially, podcasting was to allow individuals to distribute their own radio-style shows, but it is use in school lessons, official or unofficial affairs, such as conference meeting or to distribute some important messages. Furthermore, podcasting is playing a significant role in education since its convenience of sharing information anytime and anywhere. Teachers can record their and communicate the curriculums or anything else complementary through podcasting, while students absent in class could download the recorded lesson and assignments.