A tag editor (or tagger) is a piece of software that supports editing metadata of multimedia file formats, rather than the actual file content.

These are mainly taggers for common audio tagging formats like ID3, APE, and Vorbis comments (for example Windows Media Player and iTunes), but can also be taggers for JPEG, PDF and TIFF metadata (for example iPhoto).

Peekvid.com was a Web site that cataloged links to various TV shows and movies to make them more easily accessible to the public.

Peekvid did not host any video clip content itself; users provided the links, categorized them, and uploaded them to the site.

Video hosting sites that were linked to Peekvid included YouTube and Dailymotion.

ID3 is a metadata container most often used in conjunction with the MP3 audio file format.

It allows information such as the title, artist, album, track number, and other information about the file to be stored in the file itself.

iTunes (or) is a media player, media library, online radio broadcaster, and mobile device management application developed by Apple Inc. It is used to play, download, and organize digital downloads of music and video (as well as other types of media available on the iTunes Store) on personal computers running the macOS and Microsoft Windows operating systems.

The iTunes Store is also available on the iPhone, iPad, and iPod Touch.

MPEG-1 and/or MPEG-2 Audio Layer III, more commonly referred to as MP3 (or mp3), is an audio coding format for digital audio which uses a form of lossy data compression, which are data encoding methods that use inexact approximations and partial data discarding to reduce file sizes significantly, typically by a factor of 10, in comparison with a CD, yet still sound like the original uncompressed audio to most listeners.

Compared to CD quality digital audio, MP3 compression commonly achieves 75 to 95% reduction in size.

MP3 files are thus 1/4 to 1/20 the size of the original digital audio stream.

This is important for both transmission and storage concerns.

The basis for such comparison is the CD digital audio format which requires 1411200 bit/s.

A commonly used MP3 encoding setting is CBR 128 kbit/s resulting in file size 1/11 (=9% or 91% compression) of the original CD-quality file.