Short answers, pulled from the story.
The first loan in recorded history was a grain transaction between two farmers in ancient Mesopotamia where one farmer lent seeds to another with the expectation of repayment plus a portion of the future harvest.
Loans in ancient Sumer were recorded on clay tablets with cuneiform script detailing the amount lent the interest rate and the repayment terms.
Secured loans require the borrower to pledge an asset as collateral which the lender can seize if the borrower defaults while unsecured loans rely solely on the borrower's creditworthiness without requiring collateral.
The history of subsidized loans dates back to the mid-20th century when governments began to recognize the importance of education in driving economic growth and social progress.
Bridge loans serve as a temporary financial solution designed to bridge the gap between the need for immediate funds and the availability of long-term financing often used when a buyer needs to purchase a new property before selling their current one.
In the United States the Internal Revenue Code and Treasury Regulations provide the framework for determining how loans are taxed with the general rule being that loans are not considered income to the borrower.