Coronavirus: What is contact tracing and how does it work?
Governments around the world are proposing contact tracing as a way of limiting the spread of coronavirus after lockdown.
Nations are recruiting thousands of people to do the task manually, but smartphones apps that can automate the process will also have a role to play.
BBC Click's Chris Fox explains what contact tracing is, and some of the methods that have been proposed.
See more at Click's website and @BBCClick, external