"Insurance" organizations, who collect premiums for providing either life or property/casualty coverage, created their own types of loan agreements. "Banks" and "Insurance" organizations loan agreements and documentation standards evolved from their individual cultures and were governed by policies that somehow addressed each organizations liabilities (In the case of "banks," the liquidity needs of their depositors; in the case of insurance organizations, the liquidity needs associated with their expected "claims" payments).
The loan deferment process involves contacting the lender, submitting a deferment application, and undergoing the application process. The actual process can vary by lender. Other factors taken into account include the borrower's credit history, type of loan, and number of payments being deferred. Approval can take less than 24 hours to several weeks.
For commercial banks and large finance companies, "loan agreements" are usually not categorized although "loan portfolios" are often broadly characterized into "personal" and "commercial" loans while the "commercial" category is then subdivided into "industrial" and "commercial real estate" loans. "Industrial" loans are those that depend on the cashflow and creditworthiness of the company and the widgets or service that it sells. "Commercial real estate" loans are those that repay loans but that depend on the rental revenues paid by tenants who lease space, usually for extended times. More granular categorizations of loan portfolios exist but these are always variations around the larger themes.
Private student Loans is another alternative that comes into force rescuing students who have a bad credit history. I have heard of many cases where students apply for loans as a supplement with their Stafford or Perkins loans. In other cases, I have seen people applying for student loans with private organizations when their Stafford loan amount comes to an end.