Postconditions are specific conditions or states that must be true after a particular operation or process has been completed. They help define the expected outcomes and ensure that the operation has achieved its intended purpose. For example, in programming, postconditions can specify what values certain variables should hold after a function has executed. In the context of software development, postconditions are often used in conjunction with preconditions, which outline the necessary conditions before an operation begins. Together, they help developers understand the requirements and results of their code, ensuring that the software behaves as expected. This practice is essential for maintaining code quality and reliability.