Initialism of National Historic Site.
"The NHS and other health services were present at the conference to discuss new policies."
plural of NH
In plain English: The NHS is Britain's free public healthcare system that provides medical treatment to everyone living there without charging at the point of service.
"I need an appointment at the nhs to check my blood pressure."
Initialism of National Health Service.
"The NHS provides free healthcare to all residents in the United Kingdom."