Refactoring techniques are methods used to improve the structure and readability of existing code without changing its external behavior. These techniques help developers make code more efficient, easier to understand, and simpler to maintain. Common refactoring techniques include extract method, where a portion of code is turned into a separate function, and rename variable, which improves clarity by giving variables more descriptive names. Another important technique is inline method, where a method's body is moved directly into the calling code if it is not complex enough to warrant its own function. Additionally, replace magic numbers involves substituting hard-coded values with named constants, enhancing code readability. These techniques contribute to better software quality and facilitate future development.