Podcasting: A portmanteau word combining iPod and broadcasting.

Godcasting: This is a wordplay off of podcasting by throwing God into the mix.

iPod: A portable digital audio player produced by Apple. Not the first, not the last, definitely not the cheapest.

MP3 player: Any portable device that can download mostly MP3 files from a laptop or desktop computer for later playback through headphones while walking the dog.

MP3 file: A form of digital encoding for audio that can be played back on a computer or portable device. It is a popular format because it "compresses" the original audio, throwing out stuff that is normally imperceptible by anybody except your dog. But if an MP3 file is compressed too highly, it sounds bad, even to your grandmother.

Web server: A machine with a URL that can store and serve up your sermons, web pages, or blog.

RSS feed: A text file, written in a tagging system called XML (extensible markup language) that surrounds normal text, like your sermon title, with tags like Your Sermon Title. It's related to HTML.

XML feed: Another name for RSS feeds or ATOM feeds.

ATOM feed: A variation on the RSS feed that some guy invented to upset the rest of the Internet.

Subscribe to a feed: This is what a user does when they add your RSS feed URL to their favorite podcatching client. Money does not necessarily change hands.

Podcatcher: A piece of software installed on a computer that allows listeners to subscribe to RSS feeds and download MP3 files by the truckload—all automatically. Most podcatching software also provide functions to synchronize the fresh content with your favorite portable MP3 player, or you can listen to the new files directly in the software. Think iTunes, iPodder, and iPodderx. Many weblog News Aggregator software tools are doing this, too. Think Newsgator or FeedDemon.

Weblog/blog: Weblog is another portmanteau created from "Web" and "log." Weblogs are usually managed by special software residing on a Web server. They often provide automatic template tools and other nifty widgets like the ability for you to add content without knowing HTML, and allowing users to comment on your posts without knowing you.

Moveable Type: A commercial weblog package created by Six Apart and usually hosted on your Web server. Widely used.

WordPress: A widely-used, free weblog package created by a bunch of people. It's usually hosted on your Web server, but WordPress.com also offers free hosting.

Blogger: A blogger, while not walking his dog, or recording a podcast, posts articles, thoughts, commentary, and cat photos to a weblog. "Blogger" is also the name of a free, hosted weblog community owned by Google.

TypePad: An inexpensive weblog community owned by Six Apart.

Condenser mic: Also known as a capacitor mic, this is a kind of microphone with a thin diaphragm inside that vibrates between plates with a fixed electrical charge in response to sound. These mics require a power supply and produce superior sound.

Dynamic mic: The dynamic mic uses a diaphragm, too, but a magnet is stuck to the vibrating diaphragm, which sends a current through the wire to your recording device. These microphones are cheaper, but produce a lower-quality sound.

Phantom power: This is a method of supplying power to a microphone, usually a condenser mic, so that the charged plates are sensitive to the vibrating diaphragm.

Audio mixer: A device with plugs for microphones and line-in/line-out jacks. They combine and route audio signals, and can change the signal strength, audio tone, and dynamics of two or more audio signals. Some boards can optionally provide phantom power to diaphragm mics. Some mixers also amplify the signal before sending it out for recording. Some recording devices have on-board mixers. It's confusing.

Compressor: Not to be confused with "Audio compression," a compressor changes the dynamic range of an audio signal to improve the perceived quality of the sound. Compressors allow you to determine how quickly a sound is modified (attack) and how quickly it lets the sound return to a normal level (release). A limiter is a stronger, faster compressor.

Audio compression: This is a method of removing generally imperceptible elements from an audio signal so that no loss of quality is suffered. It also allows the file to use less disk space.

Noise: This can refer to background (ambient) sounds like traffic, air conditioners, or computer fans. But it also refers to electrical noise generated by sound cards or any electrical source close enough to your recording instruments to generate radio frequency interference. Generally, everything with an electrical signal attached to your microphone, your mixer, your computer, etc., generates a bit of electrical noise.

Noise reduction: This is the task of removing ambient noise and signal noise from your audio recordings. Generally, it's better to remove the noise before recording since too much noise reduction during processing can make your audio file sound muddy.

WAV file: This is a digital audio format that is uncompressed and can store a significant amount of data. Sound recordings in the WAV format can occupy a lot of disk space. For this reason, it is impractical to podcast using the WAV file format.

Equalization: Equalization selectively strengthens or weakens select portions of the audio range to improve the perceptible quality. Usually, the human voice falls between 80 Hz and 11,000 Hz, with the bass frequencies at the low end. Hiss reduction often involves lowering the signal strength of the high-end frequencies.

Pop elimination: There are two kinds of pops. The first is created by the speaker explosively forcing air past pursed lips, like saying the word "pop!" The other kind is created by spikes in electrical power and is a special sort of electrical noise. Most software applications can deal with this kind of noise spike automatically, but especially loud pops may need to be dealt with by cutting out that section of the audio.

Normalization: This is a process where audio volume is increased or decreased for the entire recording so that the sound levels don't exceed or drop below a given threshold.

Bit rates: This refers to how many bits of data will be used for one second of recording. The more bits are used for each second, the higher the quality of the recording. See "Recommended Bit Rates for Audio Recording."

Intro and outro: These are the audio snippets, voiceovers, and sound-beds that are attached to the beginning and ending of a recording. They help "brand" a podcast, and give it a consistent sound from one recording to the next.

FTP client: This is an application that allows you to transfer files from your computer to another computer on the Internet, usually a Web host or an FTP host.

Digital recording: This is a digital representation of an audio sound in 1's and 0's. It is differentiated by analog recording, which uses physical media to capture sound as a continual wave form. It is played back with another physical device, such as a needle on a vinyl record

Podcastsphere: This refers to the entire world (sphere) of podcasts and podcasters on the Internet at any given time. It is a term inspired by "blogosphere," which means the same thing, but for blogs and bloggers.

Sample rate: Where bit rate refers to the amount of data used to store a second of sound, the sample rate refers to the number of times per second a sound is sampled to make a signal. A sample is a value, or a set of values, representing a sound at a single point in time. The higher a bit rate, the more samples can be stored in a file. Lower bit rates support much lower samples. As with bit rates, the higher the number, the better the audio quality. Samples are measured in Hertz (Hz), just like frequencies are. Typically, you want a sample rate that is twice the number of Hz of the frequencies you are recording. Since the human voice can generate frequencies up to 11,000 Hz, you should record with a 22,000 Hz sample rate, at least. Phones generate an 8,000 Hz signal, radio broadcasts are typically 22,050 Hz, and CDs are typically recorded at 44,100 Hz. Most vocal MP3 files can survive encoding somewhere between phone and CD-quality audio.

Stereo/mono: For most audio files, this refers to whether there is a different signal encoded for the left vs. the right channel. Adding a stereo channel to a file typically doubles its file size. However, MP3 audio can encode just the differences between the left and the right channel, thereby allowing for stereo recording without dramatically increasing the file size.

ID3 tag: MP3 files allow for some textual information to be encoded in the file itself so that search engines and MP3 players can know something about the file. Typical information encoded in the file includes the song title, the artist name, the track number, the genre, copyright information, and so on. Most audio production software allow you to edit the ID3 tags in production, but it's often useful to have a standalone application that can do this more easily.

Podcast directories: These content directories on the Internet are distinct from Web directories in that they only list podcasts and podcast sites. Often, these directories have a "ping" service available, so that when you update your RSS feed with a new podcast, you can manually ping the directory, notifying it that your new show is available. Some weblog tools can be configured to automatically ping any directory you specify every time you publish a new feed. If you're rolling your own feed, there are tools that you can download to manually ping your favorite directories yourself.

Feedburner.com: Instead of publicizing your single feed address, you can tell FeedBurner where your RSS feed resides, and it will burn, or recreate, your feed on their server. The primary benefit in doing this is that FeedBurner will dynamically create a version of your feed that is suitable for most of the podcatchers and feed directories out there. That way, you don't have to master all the intricacies of iTunes special tags: XML, RDF, ATOM 1.0, and RSS 1.0 through RSS 2.0. Further, FeedBurner provides long-term statistical reports on how many subscribers you have and where they're coming from. FeedBurner offers both a free and commercial version of their service.

Rich Tatum is online-media managing editor for Christianity Today International and was the original webmaster for PreachingToday.com.