Podcast Glossary

Terms and definitions related to podcasting, sorted in ascending order:


An Aggregator (also known as a feed reader) is a piece of software designed to check any content-providers that a user has subscribed to, for updates to their content. If an update is found, the aggregator can automatically download it for the user.


Atom is a type of XML format (Extensible Markup Language) used for broadcasting web feeds. It is similar to RSS in that it can contain information about latest podcasts and then links defining where they can be found. Atom is readable by some aggregators.

Audio Producer

Audio Producers are the people that work in the lab to ensure that that all of Podlab’s audio output has been distilled to its maximum possible quality.


Often measured in the audio world in kbps (kilobits per second), bitrate is effectively one of the measurements that defines the quality of a podcast. As a very general rule, the more data (kilobits) used to make 1 second of audio, the higher the quality.

Embedded Flash Player

An embedded flash player is an audio or video player that is embedded into (ie: a fundamental part of) a web page. It typically offers streaming, play/pause/stop controls, a seek slider and a volume control. Podlab’s audio players use Adobe’s Flash technology – one of the most popular browser plug-ins on the web.


In podcasting terms, encoding is effectively the process of turning analogue audio waves into a digital format for use on the Internet. As the name suggests, encoding turns one type of information into digital code that can be transmitted online.


Hosting refers to the physical location where the podcasts are kept and transmitted from. As podcasts can be very large files, it is imperative that the host servers can cope with a high volume scenario of hundreds of simultaneous downloads, without crashing or slowing down.


HyperText Markup Language is the code and syntax for composing documents on the World Wide Web.


iPod is Apple’s ubiquitous MP3 player. Although by no means the first MP3 player, the iPod was the first MP3 player to gain such popularity – According to Apple’s quarterly financial results (up to Quarter 1 2007), total iPod sales have now reached over 88,701,000 units.


iTunes is Apple’s media player software that is packaged with their iPod. It is also available for non-iPod owners as a free download, and can be used to manage podcasting feeds, as well as to purchase music from the iTunes online music store.

Load Balanced Hosting

Load balancing is the art of spreading hosting-load across a number of different servers, to ensure that users always experience fast download speeds and reliable downloads. It is often necessary for the hosting of podcasts, due to the likelihood of many users downloading very large files simultaneously.


In podcasting, mastering is the name given to the process of preparing a final high-quality copy of a podcast, that can then be encoded for distribution to users.


A micro-site is the name given to a website with a single purpose, that is produced as an off-shoot of a ‘main’ website. In podcasting, micro-sites are often used to solve the difficulties associated with the hosting and streaming of podcasts.


In podcasting, the .m4a file extension is a type of compressed audio often associated with Apple’s iTunes. MPEG-4 Part 14


An encoded file containing audio data. Although it has been largely superseded by MP3, an MP2 performs better than MP3 on high bitrates (256 to 384 kbit/s) and is generally more error resilient than MP3. As such, higher quality recordings of podcasts may be encoded in MP2.


Audio podcasts may be encoded and distributed as MP3 files which compress the data more than an MP2, and yet still sound like a faithful reproduction of the original uncompressed audio to most listeners.

MP3 pro

MP3 pro combines MP3 files with a type of compression which allows for the distribution of podcasts which are half the file size of normal MP3s, having compromised very little in audio quality.


For many programming languages, a namespace is a context for identifiers. For example, within XML, it would allow an aggregator to identify a feed by the RSS or Atom namespace prior to the start of the feed.


A newsfeed (or content feed/feed/web feed/xml feed) enables an aggregator to establish whether content has been updated on a particular site by providing an up-to-date summary of the site. Links within the feed then enable the aggregator to download new files such as recently added podcasts from the site.


Ogg is a standard format which allows digital multimedia such as podcasts to be streamed efficiently over the internet.


A podcast is a digital media file (usually audio or video) that is shared over the web using web feeds, for playback on portable media players and computers.


RSS files are XML-based in format and allow for the syndication of data to be used in web feeds. A typical file could contain the details of updated or new podcasts on a site, and a link to the files.

Sample rate

The sampling rate, sample rate, or sampling frequency defines the number of samples per second (or per other unit) taken from a continuous signal to make a discrete signal. For podcasts, the greater the number of samples per second, the higher the quality of recording, but the larger the file size.


Streaming enables clients to experience an uninterrupted audio or video podcast from the site provider, whilst making it unnecessary for them to fully download the file prior to listening to it.


A vodcast (video podcast or vidcast) is a term used for the online delivery of a vidio clip on demand via Atom or RSS enclosures.

Web Syndication

This allows a section of a website to be made available for other sites or publications to use simultaneously Recently added/updated podcasts could be syndicated into a newsfeed and downloaded by many people.


Windows Media Audio is an encoded and compressed audio file format. It was initially intended to be a competitor to the popular MP3 format.


The World Wide Web Consortium (W3C) is an international consortium where Member organisations, a full-time staff, and the public work together to develop Web standards. Many important web technologies, such as HTTP, HTML, Atom and PNG are created and maintained by W3C.


eXtensible Markup Language is used for defining, storing and exchanging data on the Web. XML is similar to HTML but does not have any predefined elements, and is therefore extensible to various contexts, such as databases or newsfeeds.