What is the Covid-19 antiviral pill?

Earlier this month the UK medicines regulator, MHRA, approved the first pill to treat the symptoms of coronavirus. With life feeling more normal by the day but case rates remaining high, this is a breakthrough for the treatment of the virus at home. 

Since the beginning of the pandemic, vaccines have always been the golden ticket out of the pandemic. Now, Molnupiravir has been shown to cut the risk of hospitalisation or death by half, but how does it work?