Testing is a crucial process in software development that ensures applications function as intended. It involves executing a program to identify bugs or issues before the software is released to users. By conducting various types of tests, developers can verify that the software meets its requirements and performs reliably under different conditions. Unit testing, a specific type of testing, focuses on individual components of the software. This helps catch errors early in the development cycle, making it easier to fix issues before they escalate. Overall, testing enhances software quality and user satisfaction.