Traditional lending where the cash flows of the business pay interest and amortizations. This suits rather mature companies.

Borrowers that have assets to pledge. Those assets can be real estate, loans, invoices, machinery, vehicles etc etc. Debt levels can be significantly higher than in cash flow lending as the loan is secured by assets that have some resale value. Loan-on-loan financing falls in this category.

Typically caters to growth companies with negative EBITDA and limited assets. More expensive than traditional debt but still a lot cheaper than equity.

Topline, rather than, bottom line financing. The lender will take comfort in the ARR/MRR of the borrower. Works well for subscription based business models.