The purpose of collateral is to secure your loan. Banks ask for collateral in order to get back their investment in a situation you cannot pay back. You can use land, house, gold, stocks, etc. as collateral when applying for a loan from banks. You also need to provide proof of income to convince the bank that you can repay. However, there are financial institutions that do not need collateral, for instance microfinance and saving and credit cooperatives also do not ask for collateral but you still need to get guarantor for loan approval. You might also need to be a share holder in these companies.