Many health insurance policies require patients to call and get preapproval for tests or procedures. the health insurance company acts as a for the purchase of these medical services.

The health insurance company acts as a middle man for the purchase of these medical services. The process is you enroll in a health insurance and pay them on a monthly basis to save for future emergencies. Then, the health insurance company will be the one to communicate with the hospitals for health services. 

   The explanation gives the reason as the cause of some fact or claim, while the argument provides support in the form of evidence or example in order to substantiate the claim.

Explanation:  An explanation is any statement, reason or justification that makes a certain belief, action or position clear. An explanation can also mean a scientific explanation or explanation in the learning process.

The argument is a reason or set of reasons, settings, which support a particular idea or theory. The argument may also mean the exchange of ideas and attitudes within a discussion when opposing opinions, i.e. when a claim is supported by an example that serves as an argument.