A more thorough explanation:

Definition: Payer refers to a person or entity who is responsible for making a payment, especially for a negotiable instrument.

Example: If you have health insurance, your insurance company is the payer for your medical bills. Similarly, if you write a check, the person or organization who receives the check is the payee, and the bank or financial institution that processes the payment is the payer.

The examples illustrate that a payer is someone who is responsible for making a payment, whether it is for medical bills or a check. The payer is the one who is obligated to provide the funds for the payment to be made.