The NHS in England has become more difficult to understand since the reforms brought about by the Health and Social Care Act 2012. There is no agreement about who is in charge or where the service is going. There is a more active market where organisations providing health care have to compete to win tenders. There are more diverse providers, some commercial and some voluntary sector. Hospital services are still largely provided by NHS Trusts. One small trust, Hinchingbrooke, has been handed to a private company to run (though the building still belongs to the NHS and the staff are still NHS employees). Markets, in the sense that individual patients choose where to go for treatment, have not developed much.
An alternative guide to the new NHS in England by the Kings Fund:
an introduction to the new NHS in 6.5 minutes.
How did we get here?
Diagrams showing the structure of the NHS at various points since 1948