Google Chrome is built upon Chromium open source project, Google chrome is packaged and distributed by Google officially. In-short Google Chrome is a commercial and closed source product by Google which is based on open source Chromium project. Chromium, being open source is mostly used by Linux operating system users. For example: Chromium is available in Ubuntu repositories and one can download it from Ubuntu Software Centre, it maintained by Ubuntu developers and goes through their stable release and update process, same thing happens with other Linux distros and this makes Chromium more compatible for Linux based operating systems.
Another key difference between Google Chrome and Chromium is chrome is red where as Chromium is blue in color ;-) You should know that both web browsers share majority of code and features, only a few minor differences makes them a little bit different from each other.
For creating Chrome from Chromium, Google uses its source code and adds following features:
- In-built print preview and print system
- Google name and a different logo trademarked
- In-built PDF viewe with proprietary license and code
- Auto-update and tracking system called GoogleUpdate
- Integrates Flash Player with proprietary license and code
- Opt-in option for users to send Google their usage statistics and crash reports
By default Chromium only supports Vorbis, Theora and WebM codecs for the HTML5 audio and video tags whereas Google Chrome supports these as well as AAC (patent-encumbered) and MP3 (formerly patent-encumbered). Although there are more differences but these are the technical ones which affect user user experience.