is a kind of step down E.R. Sometimes they are private and sometimes physicians services use them to cover their patients for unscheduled visits . I worked at one that was staffed by the M.Ds of the service who rotated service. It kept the general practitioners current in things like suturing , anaphalaxis and broken bone emergencies and allowed people who had painful problems like UTI or sore throats. to receive treatment quickly . We gave IV fluids for excessive vomiting and had a lab to check for strep, etc.
Chest pain that looked serious was sent to a hospital in an ambulance. It was a walk in clinic rare and people rarely had to wait longer than 1 hour.People's visit records were sent to their M.D. and a follow up appt was made before they left.

We need more of these.

I can't say this is true about all urgent care clinics but the one in the county in which I work as a paramedic is constantly calling us to transfer it's patients to the local hospital. As far as I can determine they can't even deal with a simple fracture or abdominal pain complaint. It pretty much seems that if you go there with anything other then the common cold they call us to take you to the ER anyways.