Who is Charlie Gard, what is the disease he suffers from and what has been decided?

It has been a heartbreaking legal battle that has captured international attention and drawn offers of support from Donald Trump and the Pope. Now, the parents of terminally-ill baby Charlie Gard have ended their legal battle over treatment for their son. Their lawyer said that recent scans had confirmed that damage to Charlie's muscle and tissue was irreversible and said "it is now too late to treat Charlie". The couple felt that continuing their fight would cause Charlie pain.  Great