# DeFi Loan

Decentralized finance (DeFi) is a rapidly growing sector of the blockchain
ecosystem that is transforming the way we think about financial instruments and
services. DeFi offers a wide range of innovative financial products and
services, including lending, borrowing, spot trading, margin trading, and flash
loans, that are accessible to anyone with an internet connection and a digital
wallet.

One of the key benefits of DeFi is that it allows end users to access financial
instruments and services quickly and easily, without the need for complex
onboarding processes or the submission of personal documents such as passports
or background checks. This makes DeFi an attractive alternative to traditional
banking systems, which can be slow, costly, and inconvenient.

In this tutorial, you will learn how to create a DeFi platform that enables
users to lend and borrow digital assets from each other. The platform you will
build will be powered by a blockchain, which provides a decentralized and
immutable record of all transactions. This ensures that the platform is
transparent, secure, and resistant to fraud.

A loan is a financial transaction in which one party, the borrower, receives a
certain amount of assets, such as money or digital tokens, and agrees to pay
back the loan amount plus a fee to the lender by a predetermined deadline. To
secure the loan, the borrower provides collateral, which may be seized by the
lender if the borrower fails to pay back the loan as agreed.

A loan has several properties that define its terms and conditions.

The `id` is a unique identifier that is used to identify the loan on a
blockchain.

The `amount` is the amount of assets that are being lent to the borrower.

The `fee` is the cost that the borrower must pay to the lender for the loan.

The `collateral` is the asset or assets that the borrower provides to the lender
as security for the loan.

The `deadline` is the date by which the borrower must pay back the loan. If the
borrower fails to pay back the loan by the deadline, the lender may choose to
liquidate the loan and seize the collateral.

The `state` of a loan describes the current status of the loan and can take on
several values, such as `requested`, `approved`, `paid`, `cancelled`, or
`liquidated`. A loan is in the `requested` state when the borrower first submits
a request for the loan. If the lender approves the request, the loan moves to
the `approved` state. When the borrower repays the loan, the loan moves to the
`paid` state. If the borrower cancels the loan before it is approved, the loan
moves to the `cancelled` state. If the borrower is unable to pay back the loan
by the deadline, the lender may choose to liquidate the loan and seize the
collateral. In this case, the loan moves to the `liquidated` state.

In a loan transaction, there are two parties involved: the borrower and the
lender. The borrower is the party that requests the loan and agrees to pay back
the loan amount plus a fee to the lender by a predetermined deadline. The lender
is the party that approves the loan request and provides the borrower with the
loan amount.

As a borrower, you should be able to perform several actions on the loan
platform. These actions may include:

* requesting a loan,
* canceling a loan,
* repaying a loan.

Requesting a loan allows you to specify the terms and conditions of the loan,
including the amount, the fee, the collateral, and the deadline for repayment.
If you cancel a loan, you can withdraw your request for the loan before it is
approved or funded. Repaying a loan allows you to pay back the loan amount plus
the fee to the lender in accordance with the loan terms.

As a lender, you should be able to perform two actions on the platform:

* approving a loan
* liquidating a loan.

Approving a loan allows you to accept the terms and conditions of the loan and
send the loan amount to the borrower. Liquidating a loan allows the lender to
seize the collateral if you are unable to pay back the loan by the deadline.

By performing these actions, lenders and borrowers can interact with each other
and facilitate the lending and borrowing of digital assets on the platform. The
platform enables users to access financial instruments and services that allow
them to manage their assets and achieve their financial goals in a secure and
transparent manner.