How does the Welsh ambulance service work?

Wales is the only UK nation to see an improvement in the time it takes ambulances to reach the most critical 999 calls, new BBC research has found.

The health secretary said it showed a "better service with a better outcome for patients".

It follows radical changes last year in the way 999 calls are prioritised.

But like other UK colleagues, Welsh ambulance crews are facing worsening delays in handing over patients when they get to hospital.

Here is an animated guide to the ambulance service in Wales and the issues it faces.

Video by Gwyndaf Hughes