90 day visa to iqama

I was offer a teaching position by a company in saudi Arabia. I had to send my passport off to an agent, and he took my passport to the embassy. They put a visa in my passport that is valid for 90 days and allows me to stay for 90 consecutive days.

I can't read Arabic, so I'm not sure what type of visa this is. The company says they processed me under a "work visa" and it would be changed to an Iqama when I get there. Yet I didn't have to do a medical in England or present a police clearance. In addition, the visa was obtained in one day.

Can some one please help by shedding light on this situation? What type of visa do I most likely have? Can it be changed into an Iqama while I'm in Saudi working?

Thanks