Financial institutions are an important part of the financial market. They provide services such as financing, currency management, financial services and investment. This paper will introduce the classification of financial institutions, including banks, securities companies, insurance companies, investment companies, fund companies, futures companies, guarantee companies, small loan companies and so on.

1. Bank: A bank is a basic category of financial institutions, which mainly provides services such as deposits, loans, payment and settlement, foreign exchange transactions, bill acceptance and financial consultation.

2. Securities companies: Securities companies are mainly engaged in securities investment, fund management, financial consulting and other activities, providing investors with investment advice, portfolio management, asset management and other services.

3. Insurance companies: Insurance companies are mainly engaged in insurance claims, insurance consultation, insurance agency and other activities, providing insurance services for investors and ensuring the property safety of investors.

4. Investment companies: Investment companies are mainly engaged in investment consulting, financial consulting, asset management and other activities, providing investors with investment advice, portfolio management, asset management and other services.

5. Fund companies: Fund companies are mainly engaged in fund management, investment consulting and other activities, providing investors with services such as fund investment advice, portfolio management and asset management.

6. Futures companies: Futures companies are mainly engaged in futures investment, futures management, futures consulting and other activities, providing investors with futures investment advice, portfolio management, asset management and other services.

7. Guarantee companies: Guarantee companies are mainly engaged in guarantee consultation, guarantee management and other activities, providing guarantee services for investors and ensuring the property safety of investors.

8. Micro-loan companies: Micro-loan companies mainly engage in micro-loans, micro-credit and other activities, providing micro-loan services for investors and helping investors solve the problem of capital shortage.

To sum up, financial institutions include banks, securities companies, insurance companies, investment companies, fund companies, futures companies, guarantee companies and microfinance companies. They provide financing, currency management, financial services and investment services, and provide investors with safe and reliable financial services.