I don't blame you for being confused. Basically you have title agents and title underwriters. Both are called title companies.
The easiest way to understand it is to think of homeowners insurance companies. You have insurance underwriters like Allstate, State Farm, and Nationwide. You have agencies owned by local business people that sell the insurance.
In title insurance, the big underwriters are First American, LandAmerica, Fidelity, Chicago, Old Republic, etc. The consumer can buy directly from the underwriter, but most often buys through an agent.
In Pennsylvania where we have regulated rates, the premium paid by the consumer is the same no matter where they buy it. The variations are in service and optional fees. There is also a difference in expertise and sadly in the willingness to give regulated discounts.
Check out our title premium calculator and you'll see some of the available discounts in PA.