Popular web video codecs?

What is a codec? What are a minimum of four popular video codecs being used for video published to the web?

What is Adobe Encore?

What is Adobe Encore useful for? What kind of projects might be useful to use with this program? How are Encore projects typically viewed once the are done or outputted?

When outputting what else do we need to be concerned about other than the file format?

Other than file format, what does resolution, aspect ratio, and bit rate have to do with an outputted video file?

Most commonly used output formats

What are some of the most commonly used output formats? After a movie has been outputted how might it be used or viewed once it has been encoded into one of the common formats?

Outputting your video

What is the process to output your video or movie project out of Premiere?