Twitter is an online social networking service that enables users to send and read short 140-character messages called "tweets". Registered users can read and post tweets, but those who are unregistered can only read them. Users access Twitter through the website interface, SMS or mobile device app. Twitter Inc. is based in San Francisco and has more than 25 offices around the world. [source]
How to download videos from Twitter
1. Copy a supported Twitter url from your browsers address bar (see above for some examples).
2. Paste the url into the box above and click the Download button.
3. A list with several download links will appear. Each link represents a different video quality.
4. Choose a quality and click the download link.