Upgradable smart contracts are designed to allow modifications after their initial deployment. This flexibility addresses concerns such as bugs, security vulnerabilities, or the need for new features that can arise over time.Typically, smart contracts are immutable, meaning once they are deployed, they cannot be changed. However, upgradable smart contracts use proxy patterns or specific upgrade mechanisms to enable changes. By separating the contract logic from the data storage, developers can deploy new versions of the logic while keeping the user data intact.This upgradeability can be beneficial for maintaining the integrity and functionality of decentralized applications. It allows developers to adapt to changes in technology, regulations, or user needs without losing the existing user base or disrupting the service.However, upgradable contracts also introduce risks, such as the potential for malicious upgrades or centralization issues, since the control over the upgrade process may reside with a specific entity or group. Balancing flexibility and security is crucial to ensure trust among users.