TikTok is like a short-form version of YouTube. Users can post videos up to one minute long on the free app and choose from a huge database of songs and filters.
Comedy clips and film quotes are also on offer for users to lip-sync to.
Once a user has more than 1,000 followers, they can also broadcast live to their fans and accept digital gifts which can be exchanged for money.
The app displays videos by people a user follows and also, more prominently, content that the app chooses based on what they have watched before.
Private messaging is also available between users.
How big is it?
Since early 2019, the app has regularly appeared near the top of download charts.
During the coronavirus lockdowns, there has been a surge in interest. TikTok and its sister app Douyin - which is available in mainland China - now have an estimated two billion downloads worldwide, with about 800 million active users.
How much data does TikTok collect?
TikTok collects a huge amount of data on its users including:
- which videos are watched and commented on
- location data
- phone model and operating system used
- the keystroke rhythms people exhibit when they type
