Code refactoring is the process of analyzing existing code, identifying technical debt and code smells, and modifying specific code to improve its quality without changing user-facing behavior. It aims to enhance readability, maintainability, reusability, performance, and coding standards while preserving functionality. Code refactoring should be done incrementally with automated tests to prevent introducing new bugs or regressions. Technical debt refers to the increased cost of maintenance caused by shortcuts taken in development, which can accumulate over time and make code harder to maintain if not addressed. Refactoring is essential to avoid headaches in the future, improve code quality, and reduce technical debt. Key indicators for refactoring include duplicated code, repetitive bugs, or complex functionality that needs simplification. To measure its effectiveness, metrics such as code coverage, performance monitoring, and feedback from team members can be used.